"Sri Varadaraja Perumal Temple, Kanchi is one of the 108 Divya Desams of Lord Vishnu. The Alwars had visited this holy abode of Lord Varada and sung praising the glories of Athiyuran. The icon of Sri Varadarajar also known as Athiyuran (Athi Maram) made of Fig Tree. The temple is located on the top of Athigiri (Hasthigiri). It is said that the Narasimhar Sannadhi is first sannadhi to be built"!
Once in 40 years the original mula-murthi of Varadharaja Perumal is raised from the depths of the tank in Kanchipuram and displayed to the public for approx. 10 days. Needless to say (for most) this is a once-in-a life time experience.
Many Vaishnava's are planning to go to Kanchipuram at this time to witness the event and encourage others to also do the same.
See the article and link below for more information:
Atthi Varadar -
"During the Muslim invasion, the moolavar murthi (Lord Varadarajan) is said to have been damaged. As a damaged deity could not be worshiped, it was immersed in the temple tank. The moolavar that we see today at Kanchipuram was brought from Pazhaya Seevaram, about 20kms from Kanchipuram. In memory of this, the Utsava icon of Lord Varadarajan is taken on a procession once a year, during the Tamil month of Thai (Jan-Feb) to Pazhaya Seevaram. Lord Narasimha is also taken on a procession to Keezh Seevaram during the Sankaranthi period (Kanu).
The original moolavar of Lord Varadarajan which was immersed in the temple tank. Athi Varadan is taken out once in 40 years and placed outside for public worship for a period of 10 days. This event took place last in 1979 and the next one is slated for 2019"!