You could own Missouri's Jacob's Cave and 223 acres of land for $3.4 million.

$26 million Texas paradise for sale, includes one of world’s largest bat caves Monarch Ranch is prime real estate for hunting, fishing and adventures ...

A historic home for sale in Rochester, Minn., has tunnels or caves, which are something of a mystery. (Courtesy of Colin Michael Simmons with Lakestreet Photography) ...