All this talk about Tripura reminded me of a story from Hindu mythology:

The demon Taraka had three demon children Taarakaaksha, Kamalaaksha and Vidyunmaali. These demon princes performed severe penances towards Bhrama and won the gift of immense power. The boon that they received, granted them that they would live for a thousand years in three invincible, moving cities or forts (Tripura) and that they would be destroyed only by a cosmic arrow that would merge the three forts into one, and set them to fire. The demons, armed with this boon, wreaked havoc on the universe. At the end of the the stipulated time period, Shiva created a bow and an arrow and a charriot with the various gods and goddesses and components of the universe. With Bhrama as the charioteer, he sped across, and shot a single arrow of fire which destroyed the three cities.

Tripurantaka, is the manifestation of Shiva as the destroyer of the Tripuras.