My goodness. I was so happy to have found some small, nice information and now I wonder what is happening there. I also get a 404 now, and also from the site https://www.bolognawelcome.com/it/blog/i-portici-di-bologna when I try to download the brochure. I have sent a ticket... else my comment is just a very Italian boh.

So, IT answered me and gave me the more precise link

http://comune.bologna.it/portici/

which in fact works if I change browser/device. And looks nice! I hope they will solve the small remaining problem of incompatibility.

... you can also enjoy a wonderful translation of the porticoes' candidacy in Bologna dialect... a special gift for all of you who know Italian and want to put themselves at the test! :-D

The Imperial Palace Beijing website is now https://intl.dpm.org.cn/index.html?l=en for English. Officially it's https://www.dpm.org.cn/

I think the Shenyang Imperial Palace only has a Chinese version. The other languages have been offline for a while.
https://www.sypm.org.cn/
Also it's not difficult to pick "language" from the official site if it ever comes back.

An official website for the Rock Carvings in Tanum: https://www.tanumworldheritage.se/ (In English)