TESTING
The large concrete structure you're looking at isn't just a random wall—it's a remnant of a fascinating chapter in naval history, specifically relating to the development of early US Navy airships during World War I. This structure, sometimes referred to as a "mooring wall" or "deadman," was part of a training facility for handling large balloons and nascent airships.

The metal hooks and fixtures embedded in the wall are "cleats" – the kind used for tying off ropes, much like on a ship. In this case, they were likely used to secure the tethers of observation balloons and early dirigibles as they were moved around or prepared for flight. These airships, though primitive compared to later designs, played a role in coastal patrols and anti-submarine warfare during the war.

The informational sign in front of the wall, titled "Flying Balloons, Practice Cranes," provides more context. It explains that this site in Alameda was once a training ground for sailors learning to manage these unwieldy aerial vehicles. The "practice cranes" mentioned likely refer to the large, movable structures that would have been used to assist in the inflation, mooring, and launching of the balloons, similar to gantry cranes. The San Francisco Bay Area, with its relatively calm bay waters and strategic importance, was an ideal location for naval air stations and training facilities during both World Wars. What remains here is a tangible piece of that history, showing the innovative and often experimental paths taken in the early days of aviation.