Ruislip Lido started as Ruislip Reservoir in 1811 as one of the reservoirs for the Grand Junction Canal. There is an aqueduct which carries the canal feeder over the River Pinn. The Ruislip Lido Railway is a narrow gauge railway which all but encircles the reservoir. The reservoir was developed as a lido in 1933 but swimming is no longer allowed. It has a sandy beach and can feel like being at the seaside in the summer, with grass banks and sand banks. There is a modern pub, The Water's Edge, and a refurbished children's playground.