Unassuming home features bizarre theme room with no obvious purpose

This large contemporary home just sold for $630,000 in Nappanee, Indiana. Built in 1981, it's a large abode, featuring 7 bedrooms, 8.5+ baths, and a 3-car garage. It also include a "cave room" that the listing describes as "for kids" but I have my doubts. What purpose do you think it served? Mines of Moria battle reenactments? Paleolithic fetish play?

Full listing here.

image: Realtor.com

(via DIGG)