A rare entity among the temple architecture of Kerala, cave temples are few and arouse great curiosity. The one at Ittiva at Chadayamangalam in Kollam district – the Kottukkal cave temple is one such temple, virtually carved out from a gigantic piece of rock, lying in the middle of a paddy field. From a distance this architectural wonder gives the impression of a sleeping elephant.
The rock cut temple with the Shiva linga flanked by Nandi and Sri Hanuman is believed to belong to the Pallava period (8th century BC) and contemporaneous with the Shore Temple at Mahabalipuram near Chennai. There are two 10 ft x 8 ft rooms cut into the rocks and covered by a single rock overhead. The temple would appear like an elephant’s back from outside. The combination of Shiva linga, Nandi and Hanuman is found nowhere else in India.
A Mandapam (roof) in front of one of the rooms stands testimony to the skill of those who build this temple from a single piece of rock. The temple premise also has a well that never dries up.
Source:
http://www.mathrubhumi.com/travel/article/tourist_spots /
places_of_interests/kottukal_rock_cut_cave_temple_/110/
https://www.keralatourism.org/destination/cave-temple-kollam/337