The vast lakes play host to a number of quiet beaches, many of which have roped off areas of the lake for safe swimming. Although some of the beaches do tend to attract groups of teenagers in the evening and school holiday, it's easy to find a quiet spot if you don't mind walking a little way. Many of the beaches have a small kiosk selling Dutch fries, snacks and drinks.
There's also a shallow water play area in the summer with wooden pirate ships and other games for children.
If you decide to stay later in the day there's a fantastic restaurant, Paviljoen 't Twiske (/) which won the best of the restaurant week award in 2010 and has a magical feeling about it. It's a wooden building right on the waters edge, which is lit by strings of fairy lights.
't Twiske is accessible by car, 30 minutes biking from Amsterdam Central Station or by public transport bus 92 from Central Station to busstop Kolkweg.