YOGYAKARTA, Java, Indonesia — Java is an island of the unexpected. Located between Sumatra and Bali in Indonesia — the nation with the biggest Muslim population on the planet — Java is home to the world’s largest Buddhist temple, along with a massive Hindu temple complex that rivals Cambodia’s Angkor Wat.

TUKTUK, Samosir Island, Sumatra — Here’s a travel riddle: What’s the world’s largest island in a lake — that’s also on an island in the ocean?