Hilsea Lagoon is a shallow water body in Portsmouth, formed within the historic defences that once encircled the city. The lagoon occupies what was originally a moat system serving the military fortifications, and today it remains a distinctive water feature amid the urban landscape. The site is accessible to those exploring Portsmouth’s heritage trail, offering a glimpse into the engineering and defensive architecture that shaped the city’s development.
The lagoon is used for water sports, particularly water skiing, making it a focal point for recreational activity rather than a passive scenic spot. Its presence within the city boundaries adds a layer of historical interest—the contrast between Portsmouth’s modern urban expansion and these remnants of 18th and 19th century military planning. Those visiting Portsmouth can view the lagoon and its surroundings via the interactive map, which helps navigate the area and understand how this water feature relates to nearby streets, neighbourhoods and landmarks across the city.