It was amazing. I had never seen anything like it. The landscape had almost an alien appearance. These areas are travertine terraces. The ground in these areas is underlaino by limestone. Hot water from deep below disolves the limestone and carries it throug large cracks to the surface. As the water rises, the pressure decreases. That causes the water to cool & hot gas - mostly carbon dioxide. The water become supersaturated with calcium carbonate which becomes travertine at the surface.
The air had a strange smell caused by hydrogen sulfide gas. I thought it smelled like rotten eggs.
In the picture above, you see gray rock that has not been covered with travertine yet. The orange area is travertine.
The trees die after the ground surrouding them becomes covered with travertine. In the photo below, there is a tree that is dying because the terrace is starting to form around it.
We had a fun evening, but things took a turn for the worse on Saturday.