ASO, Kumamoto Prefecture--Tourists could enjoy the rare view of the lake in the No. 1 crater of Mount Nakadake in the Aso volcano complex here turned green for the first time in six years.

Why it's incredible: The lake is the only place on Earth that's similar to Jezero crater on Mars. Lake Salda is a body of water in Turkey that bears a strong resemblance to Mars' Jezero crater.