Panchavati gets its name from the five giant banyan trees making up the forested area where Shri Rām, Sitā and Lakshman spent a large portion of their exile. This is the first of the five banyan trees situated in front of the Sitā Gufa (Sitā cave) where she spent a lot of time during her exile.
There is a tiny cave where you can slither along, but I wimped out and waited outside while the rest of the family did the honors.