Mention Cambodia to a reasonably worldly traveler and she’ll invariably picture Angkor Wat, the sprawling temple complex in the jungle’s depths. Tourists tend to squeeze the millennia-old site into a grander tour of Southeast Asia, their sole whistle-stop in the country. But for a 21st-century perspective on Cambodia’s assets, you’d be wise to look to the coastline, which unfurls some 275 miles between Thailand and Vietnam. Over the past few years, the southern stretch, dotted with islands, has been morphing from bucolic backwater into a bona fide beach destination, with resorts rapidly materializing.
The...