Indonesia, Aug. 13 -- Hundreds of tourists, many of them young Westerners, sat on gray stone steps atop the world's largest Buddhist temple, occasionally checking cellphones or whispering to each other as they waited for daylight.

Sunrise wasn't spectacular on that recent summer day. But even an ordinary dawn at Borobudur Temple - nine stone tiers stacked like a wedding cake and adorned with hundreds of Buddha statues and relief panels - provided a memorable experience.

The 9th century temple is in the center of Indonesia's Java island, a densely populated region with stunning vistas. Other highlights include the towering Hindu temple complex of Prambanan, like Borobudur a UNESCO World Heritage site, and Mount Merapi, the country's most...