But other stuff has been:
https://www.theguardian.com/science/2017/apr/24/mexicos-ancient-city-guards-its-secrets-but-excavation-reveals-new-mysteries
I thought the idea of using mercury to represent rivers and lakes was interesting: Qin Shi Huang's tomb in China is said to have had a similar feature.
Cheers
Mick
Indeed. Here (https://www.theguardian.com/world/2015/apr/24/liquid-mercury-mexican-pyramid-teotihuacan) is the 2015 article that talked about the original mercury find. I was quite surprised - after all, it's a metal...