Camping was a popular activity among Thai school students as well as foreign backpackers to Thailand long before the buzz word 'ecotourism' came into existence.
That's because it is the cheapest accommodation to be found. Admittedly not as comfortable as staying in a hotel, resort or guest house, camping is simple, easy and gets you much closer to nature than would otherwise be possible.
The best places for camping in Thailand are in the national parks. Almost all of the 76 national parks have at least one camping site. Notable exceptions are Doi Suthep/Doi Pui in Chiang Mai, Hat Jao Mai in Trang, Nam Tok Pliew in Chanthaburi, and Thap Lan in Prachinburi, where camping is not permitted.
Some parks have tents for rent for just five to ten baht per person per night. You may have to bring your own tent along to many other parks.
It's a good idea to take your own sleeping bag or mat and other basic camping gear. You should also take a torch, rain gear, insect repellent, a water container and a small medical kit for your own convenience and safety.