USA, Alaska

Glacial caves of bright turquoise-blue color 

To see this beauty is a considerable risk, no one guarantees the safety of visitors, because the state of glaciers is quite unstable and depends on many factors. 

It is not recommended to visit these places in the summer season, when glaciers are exposed to high temperatures. 

When visiting caves, tourists should understand how dangerous it is - at any moment there is a risk of huge chunks of ice falling, up to the complete destruction of the cave.