Willen Lake

Willen Lake is a 170-acre lakeside park in Milton Keynes and the largest outdoor activity centre in the area. It runs watersports on the lake — kayaking, paddleboarding, raft building, sailing and banana boat rides — alongside land-based attractions including the Treetop Extreme high ropes course, Treetop Drop, a Splash 'n' Play water play area, crazy golf, and a large play park.

For children's parties the lake sells two packages outright: a Paddlesports Party on the water, and exclusive private hire of the Splash 'n' Play area. Treetop Extreme has no fixed party package, but groups of six or more booking its general sessions receive an automatic 10% discount.

There is a café and a bar on site, and the park itself is free to enter — you pay for the activities you book.