Butter lamps are a conspicuous feature of Tibetan Buddhist temples and monasteries throughout the Himalayas. The lamps traditionally burn clarified yak butter, but now often use vegetable oil or vanaspati ghee.
The butter lamps help to focus the mind and aid meditation. According to the root tantra of Chakrasamvara: "If you wish for sublime realization, offer hundreds of lights".
The monks in the monastery manage the actual lamps, taking extreme care to avoid starting one of the devastating fires which have damaged many monasteries over the years.