Established in 1978, this institute collects medicinal plants from remote corners of the Bhutanese Himalaya, and distributes pills, ointments and medicinal teas to regional health-care units around the country. As well as a fully functioning herbal medicine hospital, there's a small museum here covering some of the 300 herbs, minerals and animal parts that Bhutanese doctors have to choose from.

　　Of particular interest is yartsa goenbub (cordyceps) – actually the bodies of caterpillars and other bugs that have been infested by a parasitic fungus – which is consumed as a form of 'Himalayan Viagra'. The curious 'worm-root' sells for up to US$25,000 per kilogram in China. Also pause to examine the intricate 'Celestial City of Medicine' sculpture in the lobby.

　　If you're feeling under the weather, the on-site clinic will tell you if your wind, bile and phlegm are in balance and prescribe appropriate medicines or treatments, all free of charge. Lasgang root and gentiana are said to do wonders for a sore throat, while chozen nagsel helps in curing all diseases apparently caused by evil spirits.