Originally commissioned by Henry VII, it is the oldest building in Portsmouth still in active use.
The tower’s walls measure approximately 2 meters in thickness, designed to withstand period artillery fire.
During the late 18th century, it was converted into a storage facility for gunpowder, requiring strict safety protocols for those working inside.
The building was once used as a residence for the Lieutenant-Governor of Portsmouth.
Its location overlooks the entrance to Portsmouth Harbour, the primary transit point for naval vessels since the 15th century.
The Square Tower is a Grade II listed building located in Old Portsmouth, dating back to 1494 as part of the town's original defensive fortifications. It served as a gunpowder magazine during the Napoleonic Wars and functioned as a governor's residence and military storehouse over several centuries. The structure is constructed primarily of stone and features a unique vaulted basement that dates back to the Tudor period. Today, the venue operates as a flexible space hosting local community events, weddings, exhibitions, and independent markets. Its location on the harbor entrance provides a direct connection to the historic naval history of the Solent. The thick masonry walls remain a prominent example of early defensive architecture in the region.
From the Hotwalls promenade looking back at the tower with the harbor entrance in the background.
Check the official website for event-specific schedules as the building is not always open for general public walk-ins.
Walk the perimeter of the tower to observe the transition between original Tudor stonework and later modifications.
Combine your visit with a walk along the adjacent Hotwalls promenade for views of the Solent.
Do not assume the building is open to the public daily; it is frequently booked for private events.
Operates primarily as an event space; access depends on scheduled bookings and public event calendars.
