Some go to Thailand for food. Others go for the Songkran water-splashing festival.

For 30-year-old Wang Chen, however, traveling to Thailand means having your limbs stretched and manipulated into a variety of yoga-style positions, while intense pressure is applied by a masseur.

Wang is just one of many tourists visiting Thailand to enjoy a range of relaxing spa treatments.  

"The magical attraction of Thai spas is they leave you feeling relaxed and energized at the same time," Wang said, adding that Thai spas are very different from the traditional Western spa concept, based around water and oil-based treatments.

Spas were introduced to Thailand from the West in the early 1990s, initially only in luxury resorts and hotels.

Over the past two decades, Thailand's spa industry has grown rapidly, and the country has become one of the most popular spa destinations worldwide. Massage treatments are popular among travelers and locals alike, and can be enjoyed on street corners as readily as in five-star hotels.  The combination of spa treatments, traditional herbs and Thai massage, which has a history stretching back over 2,500 years, make Thai spas very special indeed.

Developed by monks, Thai massage is used to treat tiredness and pain by stretching or pressing muscle knots to relieve stress. In some types of traditional Thai massage, the massage practitioner might use their hands, fingers, elbows, knees, or even feet.

"When spas were introduced to Thailand, the combination of Thai massage with spa treatments, together with the use of local herbs, was also developed," says Kitiphat Jirakijviwat, a spa owner in Chiang Mai. "It's a perfect and unique treatment for therapeutic purposes and relaxation."

Opened in 2011, Kitiphat's Zabai Thai Spa, has won awards from Tripadvisor.com, the world's largest travel website. The spa also featured in a scene from hit Chinese movie Lost in Thailand (2012).

Kitiphat's popular spa packages include "East Meets West" options, combining massage and spa treatments.

As well as massage, Thai spas offer treatments including body scrubbing, waxing, wrapping, herbal treatments and facials. Treatments are enriched and diversified by the Thai tradition of using a variety of herbs as part of the spa experience. 

"This makes a Thai spa unique, the sights, sounds, scents, tastes and touch [creating] a full experience for the senses, helping [guests feel] completely relaxed and fulfilled," Kitiphat said.

In recent years, the Thai government has regulated the spa industry more strictly, in a bid to maintain the quality and authenticity of traditional massage treatments offered in spas, Kitiphat said.

Of the 1,463 registered spas, health shops, and other beauty facilities registered with licenses from the Public Health Ministry of Thailand as of February 2011, 454 were spas. Prices can range from around 200 baht ($6) to over 4,000 baht in the registered shops or hotels, depending on the treatment selected.

In recent years, the Thai government has regulated the spa industry more strictly, in a bid to maintain the quality and authenticity of traditional massage treatments offered in spas, Kitiphat said.

Spas need government-issued licenses as an endorsement of quality and capability. As a result, the massage treatments offered by spas are generally required to adhere to a fairly standardized, traditional model.

Instead of reinventing their massage treatments, Thai spas are putting more emphasis on diversifying the content of the packages and services they offer.

The current trend is towards more holistic health care programs, or courses combining lifestyle workshops and spa treatments, Kitiphat said.

"Some spas offer a three- to five-day stay to learn how to cook and eat healthy foods, how to practise yoga, meditation and detox programs, as well as relaxing massage and spa treatments," said Kitiphat.