During the Oer-IJ Expeditie, participants can choose between 5 different routes: 10, 17, 23, 26 and 32 km. All 5 routes consist of a real voyage of discovery. Each route shows many remnants of the old Oer-IJ and the role of wind and water in the formation and later use of this landscape. During the event, the participants will get to know the fascinating past of this green heart in Kennemerland in a special way.

The routes all start and finish close to the station of Castricum and run through the regions of Castricum, Akersloot, Uitgeest and Heemskerk.

During the Oer-IJ Expeditie there are 5 different routes:

  • 10 km – Duin and Bosroute
  • 17 km – Dog- and Katroute
  • 23 km – Molens- and Kastelenroute
  • 26 km – Langemeer- and Geestenroute
  • 32 km – Langemeer- and Kastelenroute

Molen - Oer-IJ Expeditie

10 km - Duin and Bosroute

The Duin and Bosroute is a very nice varied route where we give extra attention to families with young children. Like all other routes, this route also first goes through the ground of the Beach Finds Museum along the PWN water storage and nature development project. After this, the route continues over the area of the former psychiatric hospital Duin and Bosch with beautiful nature and old buildings. The Koningskanaal is crossed to get to the Vogelenzang lake, both are man-made with interesting history. A little further along the route is Visitor Center De Hoep where you can experience everything about the management of drinking water and nature in the dune area. The route continues through the varied dune area, where you are treated to a beautiful view of the landscape formed by wind and water.

17 km - Dog- and Katroute

The 17 km route goes over the Oosterbuurt to the strategic location of the old castle Cronenburg. Then you walk straight through the Castricummer polder, the low-lying estuary of the Oer-IJ with old creeks as current watercourses. At Uitgeest, the route passes the windmills De Dog and De Kat, each of which drains its own polder. Afterwards you can take a short break on the always pleasant Regthuysplein. The route continues to Heemskerk. Exactly where the Oer-IJ found a passage to the sea between the old beach walls. Here the route follows the northern branch of the Oer-IJ. You reach the forest edge through the horticultural strip to reach the finish underneath the Papenberg.

23 km - Molens- and Kastelenroute

This route follows the 17 km route, but after crossing the northern branche of the Oer-IJ, an extra loop follows the strategically located castle Assumburg. This is one of the 10 castles that were very close to each other in semi-arc. You hear and see the reason for this at one of the information points, in which the water also played a role. Just like the nearby inundation areas of the Defense Line of Amsterdam. After visiting the castle with its beautifully landscaped garden, the route continues along the southern branch of the Oer-IJ, which ends at Marquette Castle, which is hidden behind trees. The route then reconnects with the 17 km route.

26 km - Langemeer- and Geestenroute

From Castricum you walk to the old eastern coastline. Here, about 5.000 years ago, the narrow adjacent beach ramparts of Akersloot were formed. First habitation was possible on these beach walls, with the land being worked on early and transformed into so-called ghosts. With all the watercourses in the area, Akersloot has many little harbors where things were brought to land by water. Fishing and recreation have remained here. The route continues over the dike that must hold back the bosom water of the Langemeer, before descending to the very beautiful low-lying peat meadow area with many meadow birds. Via the old still functioning museum pumping station 1879 you can see the Dorregeestermolen as a wind-driven counterpart to drain polders. From the recreation area at the Uitgeestermeer, a mecca for water sports enthusiasts, the route runs along the harbor of Uitgeest to the resting point on Regthuysplein. The route then connects to the 17 km route.

32 km - Langemeer- and Kastelenroute

This route takes you along all the beautiful landscape features. The route is the same as the 26 km, but follows the 23 km route after Regthuysplein. After the locations where disappeared castles Cronenburg and Ackersloot stood, Assumburg and Oud-Haerlem are also visited. A route to be able to make many kilometers, but also to take time for all the beauty along the way.

Oer-IJ Expeditie Polder

Walking safe

During our events, we as an organization want to create the safest possible road situation for participants and other road users. That’s why it’s important to all to show the same walking behavior. We ask you to walk on the right as much as possible during our events. This allows us to avoid ambiguity on routes that aren’t completely closed to walkers.

Please note! Bringing (pets) animals and objects such as prams, banners, etc. is not allowed. Dogs on the course are only allowed on a leash and not in the indoor locations.


Participation with a wheelchair/handbike is possible on all routes, however the 10 km route is unfortunately less accessible with a wheelchair/handbike. This is because parts of the paths can be very loose and contain pieces of dune sand. If you want to participate in the 10 km with a wheelchair/handbike, go straight at the 9 km point at “Hof van Kijk Uit” over the Oude Schulpweg to the finish at Huis van Hilde.

On other routes, participants with a wheelchair / handbike are advised to turn right at the last kilometer at the roundabout in Castricum along Beverwijkerstraatweg and from there follow the road to the finish.