The Island of Schalkwijk (Dutch: Eiland van Schalkwijk) is a polder area on the south side of the city of Houten in the province of Utrecht. It is referred to as an island because it is surrounded by water: the Lek river and the Amsterdam-Rijn channel and Lek channel. About 1000 years ago, the area was mainly a swamp. In the 11th and 12th centuries, the reclamation began. The centrally located polders and the two villages of Schalkwijk and Tull en 't Waal date from the 13th and 14th centuries. The area has unique natural forms and character, with various cultural-historical monuments.