A spectacular rainbow formed over a volcanic lake as hikers reached the crater's edge in Indonesia. Footage shows the colourful arc stretching over the summit of Mount Ijen in East Java on June 28.

From tranquil mountain lakes to tropical hideaways, Asia is home to some of the world’s most breathtaking lakeside retreats.

Explore the best places to visit in Sumatra by region, from Lake Toba and the Mentawais to jungle treks, highland towns, and ...