Pamukkale in Turkey.
It's a really cool hot springs area where the minerals are super saturated in the water and so deposit out in calcium carbonate. Over time it becomes travertine. But just the location itself looks super interesting.
In a similar vein, the salt flats in Utah. When there's been a rain and there's standing water over the flats, it becomes a huge reflection - absolutely fantastic set piece for both some unique RP or for a really interesting battle.