London's outdoor swimming pools, known as lidos, are implementing enhanced security measures in response to a notable rise in antisocial behavior, including brawls, thefts, and intoxication, which have led to temporary closures this summer. These incidents are occurring against a backdrop of a severe heatwave and drought gripping Britain, leading to record temperatures and increased demand for public swimming facilities.
Parliament Hill Fields Lido in Hampstead Heath has experienced two closures this summer due to "inappropriate behaviour." Witnesses reported a large fight among youths over the May Bank Holiday weekend, which reportedly began after a swimmer was struck with a stolen wine bottle. Lifeguards attempting to intervene were allegedly pushed into the water. The victim sustained head injuries and required hospital treatment. Police arrested two individuals in connection with the incident, but they were later released.
In response to the escalating issues, the City of London Corporation, which manages Parliament Hill Fields Lido, has introduced stricter rules. These include a ban on individuals under 16 entering without an adult, random bag searches, additional security personnel, and mandatory ID checks. The lido has also erected 10-foot-high walls to deter unauthorized access. Despite these measures, a fight reportedly broke out among swimmers queuing for entry just days later. The increased security measures at Parliament Hill Lido were prompted by a pattern of disruptive behavior, with staff noting that fights are common during the summer, and in the past, weapons such as knives have been found in visitors' bags.
Similar issues have affected other London lidos. At Ruislip Lido, dozens of people were observed swimming despite explicit warnings against it. Tooting Bec Lido has also increased security, implementing bag checks and requiring wristbands for entry to manage surging attendances. This site can accommodate over 3,300 visitors daily, and while security guards report that overcrowding is a more frequent issue than aggression, they acknowledge that crowded public spaces can be prone to problems.
Jem Collins, who runs the online guide All The Lidos, suggested that the rise in antisocial behavior is primarily linked to casual visitors drawn by the hot weather rather than regular swimmers. She noted that prolonged queues and high temperatures can lead to increased tensions. Collins also pointed out that some visitors may have unrealistic expectations, comparing UK lidos to resort-style pools abroad, rather than the more community-focused swimming environments typically found in Britain.
Beyond the official lidos, other bodies of water have also seen disruption. In May, the Model Boating Pond in Hampstead Heath, a protected habitat for nesting birds, was swarmed by swimmers ignoring 'no swimming' signs, disturbing wildlife and leading to complaints from residents about it being treated as a "party destination."
Leisure company Better, which operates several London pools, reported a 30% increase in visitors to its sites between June and August 2025 compared to the previous year, indicating a broader trend of increased use of public swimming facilities during the summer months. This surge in popularity, combined with record-breaking heatwaves, presents ongoing challenges for managing public safety and maintaining a positive environment at these popular recreational spots.