Most of Thailand's national parks are under the control of the Royal Forest Department. Most national parks provide trekking trails for nature explorers. There are also camping sites for those who want to overnight in the parks. Trekking and camping are available in the mountainous areas all over Thailand such as Doi Luang Chiang Dao in Chiang Mai, Phu Soi Dao in Uttaradit, Thung Salaeng Luang in Phetchabun and Phitsanulok, Phu Kradung in Loei and Khao Luang in Nakhon Si Thammarat, to name but a few. Actually, trekking and camping are not new tourist activities in Thailand. But they are better managed today than ever before. Apart from trekking along the marked trails, you may also hire a local guide to take a tour deeper into a forest to explore off-the- beaten-track routes. Organized elephant trekking is another popular activity for anyone who isn't too adventurous. Where are some of the important eco-tourism sites in Thailand ? There is actually no end to the number of sites in Thailand but the main ones are: • Phu Soi Dao in Uttaradit • Phu Kradung in Loei • Doi Luang Chiang Dao in Chiang Mai • Khao Luang in Nakhon Si Thammarat • Thung Salaeng Luang in Phetchabun and Phitsanulok.