The Seattle Times

2 of 2
JEFF BAENEN / AP
Advertising

Thursday, November 7, 2013

Minn. man's cave collection is his hobby, passion

John Ackerman poses in a shaft entrance to his Temple of Doom, one of the 37 caves on his property near Spring Valley, Minn. Ackerman estimates he's spent $4 million on cave exploration and acquiring underground rights, but he doesn't charge admission to the nature groups, scientists and cavers who visit.