Trat

Trat province is Thailand's easternmost, bordering Cambodia, and home to the Koh Chang archipelago. Koh Chang itself is the country's second-largest island — mountainous jungle interior, waterfalls you can hike to (Klong Plu and Than Mayom), and beaches ranging from the developed White Sand Beach to the backpacker scene at Lonely Beach. The west coast has the swimming beaches; the east coast has fishing villages and mangrove kayaking.

Beyond Koh Chang, the smaller islands are the real draw for those seeking quiet. Koh Mak is car-free, flat, and ringed with coconut palms — the kind of island Thailand used to be. Koh Kood (Koh Kut) is the most beautiful: untouched beaches, a handful of boutique resorts, and Klong Chao Waterfall cascading into a swimming pool. The mainland town of Trat has a lively gem market (rubies from nearby mines), a charming guesthouse district, and serves as the jumping-off point for the Hat Lek border crossing into Cambodia's Koh Kong province.