A DEADLY volcano that spits bright blue lava contains the world's largest acid lake - capable of melting human skin. Kawah Ijen, is a gargantuan volcano on the island of Java, Indonesia ...

This lake contains carbonic acid, which is very harmful ... Lake Monoun Lake Monoun is in Cameroon. It is quite dangerous, with significant gas beneath the water’s surface.

Kawah Ijen is an active volcano on the island of Java with an extremely acidic crater lake and gas emissions that produce blue flames upon contact with oxygen in Earth's atmosphere.