[2] Willen Lake is Milton Keynes's most popular park,[3] attracting in excess of 750,000 visitors a year.

There are large events held on the site throughout the year, including Comedy Central's FriendsFest [6] As of 2024[update], the activities area of the park includes of a number of leisure attractions [7] including: Since January 2010, Willen Lake has also been the location of the Milton Keynes parkrun, which currently starts just to the West of the lake, then follows the Grand Union canal to Great Holm, before making a complete loop of the South Lake and finishing by the Watersports Centre.

The lake has capacity for an additional level increase of 1.3 metres, equivalent to a once in 200 years event.

Unlike most of the rest of the UK, Milton Keynes has separate storm and foul sewers, so sewage pollution is not a significant problem.

The lake is surrounded by a mixture of open parkland and woodland, which forms part of the wider Ouzel Valley Park.