A traditional Bhutanese hot stone bath uses rocks taken from the river that are heated till red hot and then placed in the bath water. The rocks then crack and steam, releasing key minerals into the water which alleviate aches and pains and are said to have broader medicinal properties.
The hot stone bath is a ritual in itself and traditionally these baths were taken close to rivers from where the best stones could be sourced. These days the practice is offered countrywide and you can opt for a luxurious version, like the one at the Gangtey Lodge (see picture above), or go for a more earthy version in a local farmhouse where the bath is laid on by your hosts. Either way it makes for a very relaxing and restorative experience, especially if you have been doing some trekking.