The Maeslantkering Climb, sometimes also ironically called Côte de Maeslant, takes you from 5m above NN to 20m in a nice, steady gradient of 6%. At 250m length, strong riders can conquer it in a long sprint in the big ring. The way down the other side offers a nice, somewhat technical, albeit short, descend. This sand hill is also the location of the "Maslantkering Challenge." Some bikers have climbed it over 200 times in succession; the current record is 700 times (2018). The prize for the winner of the challenge is a "climbing goat" that has to be donated to a children's farm. Oh well ...
The hill was built together with the Maeslantkering in the mid 90s, and was created to cheaply dump the ground excavated for the construction of the Kering (it turned out the ground did not have the right consistency and thus has been used for a different project elsewhere. However, swapping the ground still reduced the costs). Today, it serves only touristic purposes.