The brainchild of the owner’s late husband, a scuba enthusiast, the tunnels are carved into the 18-acre property. Entered via a series of grottoes and pop-up holes, the tunnels lead to a 30-foot-deep outdoor pond, which is filled with statues, faux fossils and exotic fish, according to Gary Hosack of Crown Realty, who is listing the property...

In a small city outside Kansas City, Kan., an estate with an eccentric perk—a network of underground, water-filled tunnels designed for scuba diving—is slated to list for $11.8 million.

Outside Kansas City, an estate with its own private network of underground tunnels for scuba diving is slated to list for $11.8 million. Photo: Crown Realty

In a small city outside Kansas City, Kan., an estate with an eccentric perk—a network of underground, water-filled tunnels designed for scuba diving—is slated to list for $11.8 million.

The brainchild of the owner’s late husband, a scuba enthusiast, the tunnels are carved into the 18-acre property. Entered via a series of grottoes and pop-up holes, the tunnels lead to a 30-foot-deep outdoor pond, which is filled with statues, faux fossils and exotic fish, according to Gary Hosack of Crown Realty, who is listing the property with his daughter Katie Casey. The largest of the grottoes features a 30-foot waterfall, a heated swimming pool, a sauna and a wet bar for entertaining.