which is very beautiful from the top of the crater. The Greenish lake
in the volcanic crater of Kawah Ijen looks calm and stunning. However,
it is also the largest acid lake in the world. The water in the crater
lake has a pH of less than 0.3 on a scale of 0 to 14 (7 neutral). In
fact, it is acid that makes water green. Can you swim in Ijen Crater?
No, the lake was a 90 C sulfuric acid pool that no one lived in, and
which would be very dangerous for anyone swimming in it.
Let's find out how Ijen crater is !