Sutro Heights cottage and water tower

The tank house and observation tower located at the southeast comer of the parapet and adjacent to the residence was built around 1884. This two-story building with white clapboard siding was built by Sutro to house and screen the twin 15,000 gallon water tanks located on the rear of the parapet. However, an 1886 photograph showing the building labeled as "observatory" indicates the structure's alternate use as a viewing station that provided visitors with an elevated view of the surrounding panorama. Subsequently a taller, three-story, wood observation tower of a similar design was constructed adjacent to the tank house to the north. This structure, which featured a cantilevered, glass-enclosed observatory on top, soon became a landmark recognizable from a great distance.