The Natural Resources and Environment Ministry's Botanical Garden Organisation will invest Bt50 million to build Thailand's first canopied walkway in the Queen Sirikit Botanical Garden in Chiang Mai's Mae Rim district, a senior official said yesterday.

The 350-by-20-metre walkway - to help research and stimulate eco-tourism - is still at the design process and should be completed by 2010, organisation president Withoon Karuna said.

He added that before the project starts, an environmental impact assessment would be done to prevent damage to the 6,500-rai garden, and if completed as planned, the walkway would be Southeast Asia's longest canopied walkway.

Withoon also said that though the walkway was actually intended to help research, it could boost tourism at least threefold from the current 300,000 visits per year.

At present, there are only a few canopied walkways in Asia, including one in Malaysia's Kinabalu National Park and the recently completed Lu Bukit Hijau Park, and another in the Brunei's Ulu Temburong National Park.