As London's heatwave continues, many residents are seeking refreshing outdoor swims. While popular spots like London Fields Lido, Brockwell Park Lido, Hampstead Heath Swimming Ponds, and West Reservoir Centre in Hackney often come to mind, there is a lesser-known gem just beyond the London border in Hertfordshire. This hidden swimming lake is surprisingly accessible, being only a 10-minute walk from a Tube station.
Unique Location Within a School
Unusually, this swimming lake is located within the grounds of a school, yet it is open to the general public. A short stroll from Moor Park station on the Metropolitan line leads to Merchant Taylors' School, a selective boys' school in Moor Park. The lake, known as Merchant Taylors' Lake, welcomes non-students to use its swimming facilities.
Swimming Circuits for All Levels
The open water site offers a variety of circuits, ranging from a 150-meter loop for beginners to a one-kilometer circuit for more experienced swimmers. Besides the peaceful waters, visitors often enjoy watching local wildlife, including a resident heron that frequents the pond.
Safety Measures and Amenities
Safety is a priority: a water-safety team monitors swimmers from kayaks at all times. Swimmers must wear brightly colored caps for visibility; caps can be purchased on-site if needed. On weekends, a barista serves drinks and snacks. After swimming, visitors can use changing tents or the Old Merchant Taylor building, which offers toilets, indoor changing rooms, and showers.
Opening Times and Booking
Because the lake is on school grounds, it is not always open. Morning sessions are available on Saturdays and Sundays, with evening slots on Tuesdays and Thursdays. Swimmers must be at least 16 years old. Advance booking is required online, with no on-the-day entry. Tickets cost £9.50, or £10 if booked on the same day.
This hidden spot provides a unique outdoor swimming experience for those looking to escape the heat.



