Caves.  What have they done for us lately?  According to an article in Phys.Org, for astronauts they do amazingly important things, like providing:

…a taste of working as a safe and effective team during long spaceflights. In particular, they can hone their leadership and group skills while working in a typical multicultural team found on the International Space Station. Course designer Loredana Bessone explains the similarities of caving and working in space: “The ‘cavenauts’ have to adapt to a completely new environment. Working and living underground is both physically and mentally demanding.”

Community. Collaboration. We get it. This team spelunked for six days together and the video of their experience (after the jump) is worth six minutes, especially for any adrenaline junky.