Also popular are mountain bikes tours. Most are set in the mountains of the North, and include guides and, on certain tours, back-up vehicles carrying food and overnight equipment. Bikes are also widely available in major tourists destinations, where they can be rented at extremely reasonable rates on a daily basis.

Cliff climbing is another environment-friendly activity with a growing number of participants. The most popular area for climbing is the southern province of Phang Nga, where towering limestone cliffs provide the perfect challenge.

White water rafting

Cruising on a bamboo raft along one of the several rivers that wind through the far north is a memorable way of enjoying the region's natural scenery. Mae Taeng, a tributary of the Ping River in Chiang Mai, is a favorite choice for rafters.

The Pai River

Mae Hong Son, at 180 kms in length, is the biggest and longest river in Mae Hong Son.

There are three suitable points for rafting:

• Juai Chang Kaeo to Amphoe Pai taking about 6, hours
  
• from Amphoe Pai to Amphoe Muang - taking 5 days to cover 70 kms.
  
• from Amphoe Muang to the Thai-Myanmar border - a pleasant and picturesque section of the river that can also be negotiated by long-tail boat and on elephant back.
  The most suitable time for rafting is between October and March.

Mae Kok River

This river is 130 kms. long and runs through the heart of Chiang Rai province, eventually emptying into the Mekong River, Its route flows through jungles and over towering mountain cliffs, with several hilltribes living nearby. Regular rafting trips are organized from Chiang Rai to selected destinations, and also between Chiang Rai and Chiang Mai.

Mae Klong River

In Umphang province, rafting takes visitors past the Thi Lor Jor waterfall, hot springs, and caves. The Takobi rapids add an element of hair-raising excitement along the way. In the area is also the beautiful Thi Lor Su Waterfall, Mae Tuen Sanctuary, Mae Sot

Kayaking

Specially constructed inflatable kayaks are now widely available in southern Thailand, especially in Phang Nga Bay where they are used in expeditions to discover the many extraordinary scenic features of the limestone islands and mountains that characterize this region. A number of tour companies offer a variety of expeditions, some of which last several days with overnight accommodation in tents on secluded beaches. This environmentally-friendly activity has proved extremely popular in recent years.

Sea Canoe

Sea canoeing in Phuket has launched thousand of intrepid travellers into the mysterious grottoes, caverns, and lagoons that dot the other-worldly archipelago of limestone outcrops in Phang Nga Bay.

Inland, northeast of Bangkok, whitewater canoe tours have taken off on the Nakhon Nayok river. Along three tributaries - Maduea, Nang Rong, and Tha Dan - the water is not deep, yet provides a rush of large and small cataracts. Canoeists can continue on down the main trunk of the Nakhon Nayok River to a variety of stopping-off points.

Canoeing season is only during the rainy months, June to October.

Mountain bike

Mountain biking is often described as the "intimate" way to see a country. Besides, it is environmentally friendly, with no petrol fumes to pollute the air, and provides good exercise for the traveller. A number of companies offer wellanised biking tours.

The north of Thailand is most table for this activity because of its cooler temperatures, especially from November to February. Visitors have a choice of itineraries, such as a four-day, three-night tour, which takes in some of the most popular features of the region: hilltribe villages, ancient caves, northern tea plantations, hot springs and cruises by bamboo raft through some of the remotest territory in Southeast Asia. Accommodation is in simple village lodges. The packages often include transfers by Jeep between biking sections, a 15-speed mountain bike, back-up transport for baggage and assistance throughout the tour, all meals and an English-speaking guide.

For those heading south, biking tours offer variations of half day and full day tours depending on your time and energy. Distances covered are from approximately 11 to 36 kms., and combine cycling - mostly along back roads with relatively little traffic - with elephant rides and boat transfers depending on the tour. En route, visitors can enjoy scenic rubber plantations, waterfalls, local villages, and stunning beaches.

Elephant trekking

The Thai government has called a halt to once-extensive logging, but elephants trained to work in the industry are still very much a part of the scenery, especially in Chiang Mai, Chiang Rai, and Kanchanaburi. Exciting elephant rides through the jungle, supervised by skilled attendants, are available in such places for varying lengths of time, from a few hours to a full day.

Hiking/trekking

The vast open spaces of northern Thailand make it an ideal area for hiking, particularly during the cooler months of the year (November - February). Chiang Mai and Chiang Rai are the most obvious trekking centers in the North, and a number of companies have been established to meet the growing demand for this kind of activity. Hikers can choose from a wide range of treks, which vary in distance and time to suit the widest possible audience. Particularly popular are treks in the mountainous area near Thailand's border with Myanmar and Laos. Knowledgeable guides are usually provided and indeed are advisable. Most tours include overnight stays in simple forest lodges or in hilltribe villages.

Doi Inthanon National Park

This includes Thailand's highest mountain, and is the most popular venue for hiking, with its extensive trails. Located in Chiang Mai province.

Phu Kradung

The northeastern province of Loei has long been popular with campers and hikers. The park consists of tableland rising between 1,200-1,500 meters, crowned by a 60 sq. km plateau on which a variety of temperate zone plants flourish. It is a 3-4 hour hike to the top, where a number of trails lead to scenic viewpoints, waterfalls and the main campsite.

Khao Yai National Park

Located in central Thailand, this largest of all Thailand's nature reserves has many established trails which take hikers through a combination of tropical forest, scrubland and up several steep hills.

Khao Sok National Park

Set in Surat Thani province, this park has waterfalls, caves and a huge reservoir dotted with over 100 small islands.

Khao Luang National Park

Located in Nakhon Si Thammarat, this reserve is extremely scenic with a number of waterfalls such as Karom Waterfall, Phrommalok Waterfall, Ai Khieo or Nai Khieo Waterfall, and the multi-level Krung Ching Waterfall.

Bird-watching

Although bird-watching has been a popular activity among Thais for many years, it is only relatively recently that overseas visitors have recognized the potential of this fascinating pastime. In total, almost one thousand different species of birds - some local, others migrating here - have been spotted in Thailand. Most of Thailand's national parks offer good opportunities for bird-watching.

Other locations include:

Wat Phailom

Set in Pathum Thani, this riverside location is where such varieties as the Asian openbill stork can be seen
between November and April.

Songkhla Lake

This vast area in southern Thailand is the largest inland body of water in Thailand, and is rich in water bird life. As a result, it draws people from all over the world to see Thailand's indigenous birds and species coming to the area from further afield. Long-tail boats with small and relatively quite outboard engines can be hired with or without a driver at reasonable cost from several points around the lake, such as the Post Office pier. Visitors may also access this same area from the town of Pattalung. Khu Khut Waterfowl Park, part of which is a nonhunting area, is home to flocks of waterfowl. Bird-watching season is between November and February.

Khao Yai National Park

Set in Nakhon Nayok, this park was recently selected as an ASEAN National Heritage Site. Some 318 migrant and resident bird species have been identified.

Kaeng Krachan

Kaeng Krachan in Petchaburi, is Thailand's largest national park but still relatively unknown. Bird-watchers can look for more than 250 confirmed species, among them the great hornbills and grey peacocks.

Doi Inthanon National Park

Set in Chiang Mai, this park is extremely popular with bird-watchers, and more than 383 species have been reported.

Phru To Daeng Forest

Located in Narathiwat, this is considered to be the largest peat swamp forest in Thailand. It is also abundant in wildlife and rare natural forest.