And while I have a little bit of time, here are some other links for 2019:

The Water Management System of Augsburg: https://wassersystem-augsburg.de/en/start

The Prosecco Hills of Conegliano and Valdobbiadene: https://www.prosecco.it/en/area-of-origin/visit-conegliano-valdobbiadene/

The Historic Centre of Sheki with the Khan's Palace: https://azerbaijan.travel/en/place/121-sheki-khans-palace (appears to be from Azerbaijan's official tourism bureau, but lacks details such as opening hours)

Risco Caido and the Sacred Mountains of Gran Canaria Cultural Landscape: https://riscocaido.grancanaria.com/inicio

Jodrell Bank Observatory: https://www.jodrellbank.net/

The 20th Century Architecture of Frank Lloyd Wright: https://franklloydwright.org/ (includes links to each of the eight inscribed sites on the UNESCO announcement page)

Thanks a lot, Colvin. I will be adding them.

I've added a few more from 2019, seems we have forgotten to do the excercise after last year's inscriptions.
Can use help though with finding official websites for the following:
- Ancient ferrous metallurgy sites
- Babylon
- Bagan (lots of commercial websites around but none really fit the bill)
- Hyrcanian Forests
- Jaipur City (there's a site from the ASI, but little info)
- Migratory Bird Sanctuaries
- Ombilin Coal Mining
- Plain of Jars

I don't think there is one globally for the bird sanctuaries. Here is one for the Red-Crowned Crane sanctuary:
http://www.ycwetlands.com/en

No problem. BTW, this page on the Frank Lloyd Wright foundation site has links to the remaining sites, such as the Robie House and Jacobs house: https://franklloydwright.org/eight-frank-lloyd-wright-sites-inscribed-on-unesco-world-heritage-list/

Here's an official link for Jaipur: http://www.tourism.rajasthan.gov.in/jaipur.html

Still, it lacks ticketing information (why make things easy?), so this site may be complementary: http://museumsrajasthan.gov.in/

This looks like an official tourism site from Iran, but while they have a page on the Hyrcanian Forests, it doesn't have much useful information: https://www.visitiran.ir/attraction/caspian-hyrcanian-forests