The deity in this temple is that of Ananta Padmanabha Swami (Maha Vishnu). According to the sthala purana Markadeya swami (a devotee of Siva) did penance for nearly 1400 years for the Darshan of Lord Vishnu. Then Lord Vishnu appeared to him as Ananta Padmanabha Swami in ShaliGraha form, this is in a cave. Even now pilgrims need to have a darshan of the Lord by going inside a small cave. Temple will be flooded with pilgrims during the weekends. The temple will be open throughout the day.
The huge treasure of gold coins, gold sand, gold grains, golden statues found at the Sri Padmanabhaswamy Temple.
The Padmanabhaswamy temple at Trivandrum (Kerala) is famous for its golden statue of Ananthapadmanabhan (Lord Vishnu) in the Ananthashayanam position. In Anantashayanam the lord Vishnu lies over a huge snake called Anantha above the sea.
This statue is the biggest one of Ananta Padmanabhan made in gold. This is the main deity at this temple and this statue cannot be seen in full. It can only be seen as 3 parts through 3 doors in which the head, stomach, leg of the Lord Vishnu in Ananthashayanam can be seen. People of Kerala believe that the Padmanabhaswamy is lying over the Anantha in sea and protecting this land from floods, disaster .etc.
The sound from the sea waves will travel to the temple through the secret paths under the temple.
The tunnels might have been created decades before by Kings to escape or hide from enemies at the time of attacks on temple or Travancore.
Sree Padmanabhaswamy Kshetram (Temple) is now the richest Hindu temple in the World.
When 5 secret underground chambers in this temple was opened, the treasure found was worth 1 Lakh crores (22 Billion Dollars)
Now one more chamber is to be opened which is expected to contain Treasure worth Crores.