- Scuba Diving: Thailand is a great place to do a PADI course, whether you're a total beginner or just in need of a refresher course. Most courses are affordable and staffed by experienced expatriate dive pros. Always check first that the vessels used by these outfits have valid marine safety documentation such as IMO, SOLAS, ISM, and the more recent ISPS certificates. The most popular centers -- around Ko Chang, Ko Tao, and Phuket -- have a large concentration of beautiful coral with an abundance of marine life. The best time of year for visibility is between December and February.
- Ballooning: From November to March, Thailand's cool north offers one of the few places in Asia to experience hot-air ballooning. The tour operator Earth Wind and Fire has been based in Chiang Mai for some years now and is the only certified ballooning outfit in Thailand. They offer predawn flights over the emerald rice paddies; as the sun rises, the beauty of the land will open up below you.
- Rock Climbing: The imposing cliffs at Railay Beach, near Krabi, make for some of the best rock climbing in the world. And you don't have to be an expert; beginners are welcome to sign up for an intro course and enjoy both the challenge and breathtaking views. There's a similar setup near Chiang Mai in the north.
- White-Water Rafting (Pai): On a white-water rafting tour, you can paddle through conservation areas and pass by canyon walls encrusted with fossils. Check locally for outfits that organize exciting yet safe tours from the laid-back center of Pai.
- Trekking (Northern Thailand): Trekking is a perfect way to explore the country's great outdoors; it's definitely one of the best ways to get out and up into lush jungle terrain. Many worthy not-for-profit organizations are now involved in helping hill-tribe villagers build sustainable tourism initiatives, and it is well worth your time to visit and support these commendable causes.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.