Sociëteit Standvastigheid (1781) was originally a gentlemen’s club for officers of the garrison and Orangists, which accounts for its name ‘Orange Club’. The clubhouse was located at Oude Delft 123. In 1956, the current building in the backyard was first occupied. It included an in-house bowling alley. It is a classically designed building, with striking features in the façade, including a stucco cornice, concrete window frames, wrought-iron railings and ornaments. With its French balconies, it looks like an early 19th-century mansion.