This impressive image is of the mask of Seto Bhairav (White Demon) in Kathmandu Durbar Square (which is part of Unesco but as I've posted about it already I'll just concetrate on this detail :)). It is one of the most important deities in Nepal, sacred to Hindus and Buddhists alike.
Bhairava is the terrifying aspect of Shiva, and this is one of the largest masks representing it - it is specially revealed during the Indra Jātrā religious street festival, which lasts for eight days from the 12th day of the bright fortnight to the 4th day of the dark fortnight of Yanlā, the eleventh month in the lunar Nepal Era calendar. A pipe sticking out of the mouth of Sweta Bhairava dispenses alcohol and rice beer on different days.
How terribly interesting this sounds - big thanks to Krishna, also a great photographer!