You will find information-packed boards by the access to the Waalenburg polder on the Zaandammerdijk. The Waalenburg polder, between De Waal and Den Burg, date back to the 17th century. This was originally a salt marsh; you can still see the old creeks. Because the polder is low-lying, the meadow is very wet and in some places the water is brackish. This provides the ideal environment for some extraordinary flowers, including many orchids and salt marsh plants that are resistant to salt water. Large numbers of meadow birds use Waalenburg as a breeding ground. In winter this marshland area easily freezes over making it possible to skate there.