Washington has one of the most beautiful subway stations. The brutalist design exposes the concrete walls with a repetitive pattern, creating an austere atmosphere. White light illuminates the walls from bottom, casting shadows on the concrete blocks. When you examine it carefully, the sunken parts of the blocks get deeper as it nears the ceiling and gives it more depth. We were trying to figure out what the white square tiles inside the concrete blocks were, and concluded that they were acoustic diffusers. The arched wall wraps all around to the other end and the underground subway station becomes a beautiful monolith.