Lake Tisza (Hungarian: Tisza-tó), also known as Kisköre Reservoir (Hungarian: Kiskörei-víztározó), is the largest artificial lake in Hungary.

[1] Following the reservoir's completion, Hungarians began to flock to the site for holidays, since it compared favourably with the crowded and expensive Lake Balaton, the traditional holiday site.

As a result, tourist infrastructure has been developed on the reservoir—renamed Lake Tisza—and the government has designated it an official tourism destination.

The lake (or reservoir) has a perfect ecology with a diversity of birds, plants, and animals.

The Hortobágy National Park has been a UNESCO World Heritage Site since 1999.