Tripurantaka is one among the numerous names of Lord Shiva. The story of this manifestation of Shiva is associated with him destroying three aerial cities of the asuras with a single arrow.
Tripuri were the flying cities of demons made of Gold, Silver and Iron. Demons Tarakaksha, Maya and Vidyunmali ruled over the three cities.
The three demons had propitiated Brahma and as boon asked for immortality which was denied and later they asked for three fortified aerial cities which could fly around and could only destroyed with one shot of an arrow.
The demons then with the help of Maya, master architect, built three cities in sky, air and earth. With safety of the boon, the demons defeated the devas and invaded cities in the universe. They started propagating Adharma.
Indra tried to bring down the city with a single arrow but failed. Finally, Devas, saints and human approached Shiva.
Shiva agreed to put an end to the rule of the flying cities. Vishwakarma built the chariot for the mission. The Charioteer was Brahma. Earth was the body of the chariot. Sun and Moon where the wheels of the chariots. The four Vedas became the four steds.
Brahma raised the chariot up and waited for the cities to align in a single line. This happened only for a split of a second.
Even this split of a second time was more for Mahadev Shiva, who shot the arrow through the three cities burning them down. The asuras were killed and Dharma restored.
As he destroyed the three aerial cities, he came to be known as Tripurantaka.
Temples dedicated to Tripurantaka form of Shiva are located in South India, especially in Andhra Pradesh and Karnataka.