When I started traveling from Southeast Asia to India's Goa hippie trail in the 1990s, the southern Thai islands were serene and relatively secluded. Hopping from Koh Samui to Koh Pha Ngan and Koh Tao, studded in azure seas in the Gulf of Thailand, these tropical gems were low-key and unplugged, lush paradises edged by palm-fringed beaches and clear blue water with technicolor coral reefs.







