I can only add them to the Most Beautiful Villages connection, Astraftis.
Connections are not meant to be from only one country.

Some of the "Spa" connections, can also be used for the City of Bath.

Connection: Astronomy and Astrology

City of Bath – "William Herschel came to Bath to be the organist at the Octagon Chapel and with his sister, Caroline, lived at Number 19 New King Street where they built their mirrors and telescopes and eventually in 1781 discovered a new planet, Uranus. Caroline was an accomplished astronomer and discovered three new nebulae and eight new comets." (Great Spas of Europe Nomination File, p. 295)

Connection: Benedictines

City of Bath – "In the City of Bath, the Abbey of Saints Peter and Paul occupies a central position adjacent to the King's Spring and occupies a site of a Roman temple, a Norman Cathedral and Benedictine monastery." "The baths were managed (...) for 800 years by a Benedictine monastery". (Great Spas of Europe Nomination File, p. 63, 438)

Connection: Celtic history

City of Bath – Bath: "The springs are thought to be the site of the Celtic pagan worship of the goddess Sul". (Great Spas of Europe Nomination File, p. 305)

Connection: Festivals

City of Bath – "The City [of Bath] hosts annual festivals including the celebrated Bath festival (of music) and the Mozart Festival". (Great Spas of Europe Nomination File, p. 442)

Connection: Irrigation and drainage

City of Bath – A "system of Roman and modern pipe routes is developed in Bath (...) The Roman Great Drain is constructed to discharge used water into the River Avon." (Great Spas of Europe Nomination File, p. 276)

Connection: Leprosy

City of Bath – The Leper Hospital in the City of Bath (Great Spas of Europe Nomination File, p. 66, 279)

Another - very obvious - connection for the Great Spa Towns of Europe.

Connection: Historic Resorts

Great Spa Towns of Europe – "All of these towns developed around natural mineral water springs. They bear witness to the international European spa culture that developed from the early 18th century to the 1930s, leading to the emergence of grand international resorts". (AB Ev)

Yes, it was meant like this. It's just another "subtype" in the justification.

Connection: Holy Roman Empire

Great Spa Towns of Europe – "According to a legend, Charles IV organized an expedition into the forests surrounding modern-day Karlovy Vary during a stay in Loket. It is said that his party once discovered a hot spring by accident, and thanks to the water from the spring, Charles IV healed his injured leg. On the site of a spring, he established a spa (...). The location was subsequently named "Karlovy Vary" after the emperor. Charles IV granted the town privileges on 14 August 1370." (Karlovy Vary - Wikipedia)

Connection: Located in a Former Capital

Great Spa Towns of Europe – Vichy "was the capital of Vichy France from 1940 to 1942." (Vichy - Wikipedia)

Inspired by the "Chairs" connection, I would like to propose a "Thrones" connection.

Aachen Cathedral - "The Throne of Charlemagne (...) is a throne erected in the 790s by Charlemagne, as one of the fittings of his palatine chapel in Aachen (today's Aachen Cathedral) and placed in the Octagon of the church. Until 1531, it served as the coronation throne of the King of the Romans, being used at a total of thirty-one coronations." (Throne of Charlemagne - Wikipedia)

Canterbury - "The Chair of St Augustine (...) is the ceremonial enthronement cathedra chair of the Archbishop of Canterbury in Canterbury Cathedral, Kent." (Chair of St Augustine - Wikipedia)

Golestan Palace - "The Marble Throne is a 250-year-old royal throne in Golestan Palace, Tehran, Iran." (Marble Throne - Wikipedia)

Imperial Palace - "The Dragon Throne is the throne of the Emperor of China. (...) The term can refer to very specific seating, as in the special seating in various structures in the Forbidden City of Beijing or in the palaces of the Old Summer Palace." "In Chinese history, the Dragon Throne of the Emperor of China (...) was erected at the center of the Forbidden City, which was itself regarded as the centre of the world." (Dragon Throne - Wikipedia)

Rammelsberg and Goslar - "The imperial throne at Goslar (...) was made in the second half of the 11th century and was the throne of Holy Roman Emperors and kings in the Collegiate Church of St. Simon and St. Jude ("Goslar Cathedral"), which stood in the grounds of the Imperial Palace of Goslar (Kaiserpfalz Goslar)." (Imperial Throne of Goslar - Wikipedia)

Red Fort - "The Throne of Jahangir (...) was built by Mughal emperor Jahangir (...) in 1602 and is located at the Diwan-i-Khas (hall of private audience) at the Red Fort in Agra." (Throne of Jahangir - Wikipedia)

Vatican City - "The Chair of Saint Peter, also known as the Throne of Saint Peter, is a relic conserved in St. Peter's Basilica in Vatican City". "The relic is a wooden throne that tradition claims belonged to the Apostle Saint Peter, the leader of the Early Christians in Rome and first Pope, and which he used as Bishop of Rome. The relic is enclosed in a sculpted gilt bronze casing designed by Gian Lorenzo Bernini and constructed between 1647 and 1653." (Chair of Saint Peter - Wikipedia)

Westminster - "King Edward's Chair (or St Edward's Chair), the throne on which English and British sovereigns have been seated at the moment of crowning, is now housed within the Abbey in St George's Chapel near the West Door, and has been used at every coronation since 1308." (Westminster Abbey - Wikipedia)

We had "Game of Thrones", but I guess that is something completely different. Will add this one as well! The one in Golestan Palace is truly memorable.

1. Some extra connections for Rammelsberg and Goslar. Did some reading up on the site because of my visit to the region.

Connection: Baroque

Rammelsberg and Goslar – "The town was not significantly damaged in World War II and so the historic centre has survived intact, with its original medieval layout and many Gothic, Renaissance, and Baroque buildings of high quality." (AB Ev)

Connection: Holy Roman Empire

Rammelsberg and Goslar – From the 10th to the 12th century [the town of Goslar] became one of the seats of the Holy Roman Empire. (Official description) "The rich deposits of silver ore there were one of the main reasons for sitting an Imperial residence at the foot of the Rammelsberg mountain by the Emperor Henry II; he held his first Imperial Assembly there in 1009." (AB Ev)

Connection: Hydro Power Stations

Rammelsberg and Goslar – "Today the water from the Oder Teich continues to flow reliably down the Rehberger Graben to St. Andreasberg and into Grube Samson, where it drives the turbines installed in the two underground power stations and produces hydroelectricity." (Nomination File, p. 31)

Connection: Name changes

Rammelsberg and Goslar – With the extension in 2010, the name changed from "Mines of Rammelsberg and Historic Town of Goslar" to the current name: "Mines of Rammelsberg, Historic Town of Goslar and Upper Harz Water Management System". (WHC Decision)

Connection: Renaissance

Rammelsberg and Goslar – "The town was not significantly damaged in World War II and so the historic centre has survived intact, with its original medieval layout and many Gothic, Renaissance, and Baroque buildings of high quality." (AB Ev)

Connection: Scientific Developments

Rammelsberg and Goslar – A "problem for which a solution was needed in order to make mining at great depths possible was caused by the hemp ropes and iron chains which were used to hoist the ore. (...) The invention of the wire cable by the Clausthal "Oberbergrat" (head mining councilor) Wilhelm August Julius Albert in the year 1834 solved this problem. The cable was one of the most important technical inventions of all for the mining industry and its use spread to all the mining areas of the world in a very short time. It was also an invention that made technical solutions in many other areas possible, for example in bridge construction." (Nomination File, p. 49)

Connection: Tombs

Rammelsberg and Goslar – The tomb of Henry III in the Palace Chapel of St. Ulrich. "Today a sarcophagus stands right in the centre of the cross in the lower chapel, whose cover slab has a sculpture dating to about the middle of the 13th century. (...) The sarcophagus contains (in an octagonal gold capsule) the heart of Henry III, which was interred in Goslar at his own request, and has been kept since 1884 in the Chapel of St. Ulrich." (Wikipedia - Imperial Palace of Goslar)

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2. I'm not 100% sure about this connection. What do you think?

Connection: Cultural landscape not recognized

Rammelsberg and Goslar – The AB Ev 632bis states that "the cultural landscape concept has strengthened the need for wider protection requiring the definition of an appropriate buffer zone." It suggests a "buffer zone around the whole property is proposed, essentially based on landscape considerations". (AB Ev)

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3. Adding rationale for existing connections without explanation.

Connection: Hanseatic League

Rammelsberg and Goslar – "Located close to the Rammelsberg mines, the town of Goslar played an important part in the Hanseatic League because of the richness of the Rammelsberg metal-ore veins." (Official description)

Connection: Silver production

Rammelsberg and Goslar – "The remains of the Cistercian monastery of Walkenried and the mines of the Upper Harz bear testimony to the first attempts to systematically extract non-ferrous metal ores (including silver, lead, tin and copper) in Europe, and to develop water-management systems for this purpose." (Official description)

Connection: Copper production

Rammelsberg and Goslar – "The copper, lead and tin mines of Rammelsberg mountain, in the Harz region, were worked continuously from the 11th century until the 1980s." (Official description)

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4. Since there has been a name change in 2010 with the extension, this should also be mentioned under "Site history".

As this only occurs once in one of the three AB ev's available (the one of the minor boundary modification), I don't think it's a strong case. The most recent AB ev calls it "five main groups of buildings"

Connection: Charles V

Rammelsberg and Goslar – Walkenried: "In view of the Protestant Reformation the abbey was finally declared an immediate Reichsstift (Imperial abbey) by Emperor Charles V in 1542." (Wikipedia - Walkenried Abbey)

Connection: Fatal Accidents or 'disasters'

Rammelsberg and Goslar – "A mining accident is documented in 1376, when more than 100 miners were buried and killed." (Wikipedia - Rammelsberg)

Connection: Frederick II

Rammelsberg and Goslar – "In July 1219 Frederick II held an Imperial Diet (German Reichstag) at the Imperial Palace and on that occasion received the Imperial Regalia, that Otto IV had kept at the Harzburg." (Wikipedia - Imperial Palace of Goslar)

Connection: Legends and Folk Myths

Rammelsberg and Goslar – "According to legend, the mountain was named after a knight called "Ramm", who was a henchman of Emperor Otto the Great. In 968, whilst out hunting, the knight tied his horse to a tree, in order to pursue some deer through almost impassable terrain. His charger impatiently pawed the ground with its hooves whilst waiting for his master to return and so exposed a vein of silver ore." (Wikipedia - Rammelsberg)

Connection: Octagons

Rammelsberg and Goslar – The upper chapel of the Palace Chapel of St. Ulrich is octagonal. (Wikipedia - Imperial Palace of Goslar)

Connection: Sieges and battles

Rammelsberg and Goslar – "After his election in 1152, King Frederick appointed the Welf duke Henry the Lion Imperial Vogt (bailiff) of the Goslar mines; nevertheless, the dissatisfied duke besieged the town and at an 1173 meeting in Chiavenna demanded his enfeoffment with the estates in turn for his support on Barbarossa's Italian campaigns. (...) During the German throne dispute the Welf king Otto IV laid siege to the town in 1198 but had to yield to the forces of his Hohenstaufen rival Philip of Swabia. Goslar was again stormed and plundered by Otto's troops in 1206." (Wikipedia - Goslar)

Connection: Thirty Years' War

Rammelsberg and Goslar – "During the Thirty Years' War Goslar at first tried to stay neutral, but then leaned towards the emperor's side. (...) When the army of Gustavus Adolphus advanced, Goslar was occupied by Swedish troops from 1632 to 1635." (Wikipedia - History of Goslar)

Connection: Hercules

Rammelsberg and Goslar – One of the sculptures on the historic guild house Kaiserworth depicts Hercules. (German Wikipedia - Kaiserworth)

Connection: Neoclassical architecture

Rammelsberg and Goslar – The portal building at the mouth of the Ernst-August Tunnel (Ernst-August-Stollen) in Gittelde is in neoclassical style. (German Wikipedia - Ernst-August-Stollen)

The River Tarn that starts from Mont Lozere and joins the River Garonne at Moissacin in France has 3 WHSs along the way: Causses and Cévennes, Albi and Routes of Santiago de Compostela in France at Moissacin. If you consider Tarn and Garonne one river, it would be 6 along the way: Bordeaux, Fortifications of Vauban at Blaye-Cussac-Fort-Médoc and Cordouan Lighthouse. The River Garonne that starts from Spain may have even more before it joins the River Tarn.

Nanda Devi & Valley of Flowers National Park
Foreigner Prices

Connection: Baroque

Quedlinburg – The three-story half-timbered house "Börse" was built by master carpenter Andreas Besen in the Baroque style. An inscription cites its year of construction as 1683. (German Wikipedia – Börse (Quedlinburg))

Connection: Romanesque

Quedlinburg – "The Collegiate Church of St Servatius is one of the masterpieces of Romanesque architecture." (Official description) "The castle, church and old town (...) were added to the UNESCO World Heritage List in 1994 because of their exceptional preservation and outstanding Romanesque architecture." (Wikipedia – Quedlinburg)

Connection: Tombs

Quedlinburg – "The graves of Heinrich der Vogler (Henry the Fowler), King of East Francia and his wife Mathilda are located in the crypt of the church. Heinrich's grave only contains a battered empty stone coffin; the whereabouts of the king's remains and time and circumstances of their disappearance are unknown." (Wikipedia – Quedlinburg Abbey)

Connection: Vernacular architecture

Quedlinburg – "The importance of the town rests on three main elements: the preservation of the medieval street pattern, the wealth of urban vernacular buildings, especially timber-framed houses of the 16th and 17th centuries, and the important Romanesque collegiate church of St Servatius." (AB Ev)

Contiguous National Sites
- Changdeokgung Palace Complex
- Jongmyo Shrine

https://english.chosun.com/site/data/html_dir/2022/07/21/2022072101404.html

"Now the road separating the two historic sites tunnels under a newly created 8,000 sq.m green area with 760 new trees to restore the connection between worldly and spiritual power. The reconnection creates a walking route through the heart of downtown Seoul from Gwanghwamun to Gyeongbok, Changdeok, Changgyeong palaces and Dongdaemun."