Many of Wayne Barrar’s photographs seem utterly routine. A row of urinals. A cluster of cubicles. An office break room. But look closely and you’ll notice seemingly random eruptions of rock into the spaces he’s photographing, like melted marshmallow tumbling out of a S’more. There’s a reason for that: These mundane office spaces are all located underground, often far underground, filling up excavations from defunct mining operations. Barrar, a New Zealander, has traveled in his home country, Australia and a variety of states in the U.S. in search of Nouveau Subterranea. Some of the repurposes he found make sense—-storage for old films, a paintball facility—-but others offer a wondrous sense of oddity, such as the glass-windowed office that features a computer, a bookshelf and an autographed baseball but which looks out on stout, roughly carved rock pillars and a trio of dusty-looking Christmas trees. More backstory would have been nice, but give Barrar credit for opening our eyes to a new, off-kilter and largely invisible frontier.

Through Dec. 14 at the American University Museum at the Katzen Arts Center, 4400 Massachusetts Ave. NW, Washington, D.C. (202) 885-5950. Open Tue-Sun 11-4.