This unusual 1,256-square-foot residence in Okayama Prefecture, Japan, looks like a simple wooden box from the outside. However, the interior features a surprising layout with a sunken living area set within a dug-out “pit” in the ground.

Designed by Hiroshima–based UID Architects for a couple with a young child, this residence—aptly named the Pit House—has a foundation that’s 3.3 feet higher than the road, with circular dug-out sections in the middle.

The home’s organic form embraces the outdoor environment much like a large garden pavilion. The sunken living area follows the contours of the terraced land, opening up views to the north.

Using predominantly concrete and steel, the architects built the program over six levels. The common areas are located on the ground floor, which has a sunken concrete cylinder. Above this circular “pit” lies a floating box structure supported by branch-like steel columns.

According to UID Architects’ founder Keisuke Maeda, the Pit House is designed to meld with the surrounding landscape. “It’s as if the site’s natural environment, and the architecture coexist harmoniously. The house has become a part of the landscape,” he says.

The home’s unique shape creates bright and open communal zones as well as cozy, private nooks. Plywood, exposed concrete, and cherry wood floors give the interiors a warm, almost treehouse-like atmosphere.