Lake Naplás (Hungarian: Naplás-tó, officially called Szilas-pataki flood control reservoir) is the largest lake of Budapest.

The lake is artificial, surrounded by the second largest natural reserve of Budapest, including a moorland and a forest.

Rare flora and fauna could be found here, therefore it has been a protected since 1997.

It is the natural habitat of the European pond turtle.

It can be reached from the city by car or bike, or by the nearby public transportation.