The Bruder Klaus Field Chapel's sharp-edged monolith may resemble a fortress, but its interior feels entirely different. Entering through a triangular stainless-steel door, visitors step into a dark, cave-like space. The walls taper upward, leaving a narrow opening where rain can enter. The exterior was made with horizontal formwork, while the interior used 120 vertical spruce logs. After the concrete set, the architect burned the logs for 14 days, leaving rounded imprints and a glossy surface. Glass bricks were later inserted, refracting light from above.