In the first polder of later Flevoland, there were three air watch towers in the 1950s and 1960s. They bore the names 6K1, 6K2 and 6K3, which in practice were called Karel 1 to 3 when reported. The Karel 1 was on Urk, next to the Kerkje aan de Zee, the Karel 2 was in the Emmelerbos in Emmeloord and the Karel 3 was in the Enserbos in Ens.
Air watch towers were used to scan the skies for fast and low-flying aircraft from the former Soviet Union, which were feared to fly into the country under radar to drop enemy paratroopers or bombs.
The air watch towers were built from he...
In the first polder of later Flevoland, there were three air watch towers in the 1950s and 1960s. They bore the names 6K1, 6K2 and 6K3, which in practice were called Karel 1 to 3 when reported. The Karel 1 was on Urk, next to the Kerkje aan de Zee, the Karel 2 was in the Emmelerbos in Emmeloord and the Karel 3 was in the Enserbos in Ens.
Air watch towers were used to scan the skies for fast and low-flying aircraft from the former Soviet Union, which were feared to fly into the country under radar to drop enemy paratroopers or bombs.
The air watchtowers became redundant and already demolished from the mid-1960s onwards, but the 1.8-metre-deep concrete foundation was left in the ground and can still be seen today. An information panel was subsequently placed at each of the Flevoland air watchtowers, with explanations and pictures from the time when they were still in full use.
It is interesting to have a look at one of these foundations and information panels anyway, but for those who are particularly interested in this, a cycle route has also been set out, which leads past all three former air watchtowers. This contains not only the locations of the towers, but also tips for sightseeing, catering and even accommodation locations along the way. So you can feel free to make it a multi-day cycling tour.
Incidentally, this cycle route passes a tower that does still exist: the Ramspol tower in Ens. This is similar in construction to the former air watch towers, but it is actually a lookout tower, just for the nice view of the Noordoostpolder, Kamper Island and the Flevopolder. So this tower has never been used to spot low-flying aircraft. It is, however, open daily and free to climb, so very worthwhile as a stopover.
Of course, you can start this bike tour at any location you like, but in view of the fact that you may not have your own bike (with you), our route suggestion starts at the bike hub on Schokland, where you can park for free and grab electric share bikes.
PLEASE NOTE: as of mid-March 2026, the Keileemweg on Schokland will be closed to all traffic due to the poor road surface. Therefore, do not cycle south from junction 75 to cycle junction 75, but continue for a short distance on the Oud-Emmeloorderweg and turn off to the first road on the right, the Plankenpad. This will lead you to cycle junction 61, the end of this route.
Cycle hub Schokland
Middelbuurt 3
8319 AB Schokland
Navigate to starting point
Former air watch tower Charles 3
Ens
Cafe Restaurant Chillers
Veerplein 1
8301 AH Emmeloord
Hotel Restaurant Grandcafé 't Voorhuys
De Deel 20
8302 EK Emmeloord
Former air watchtower Karel 2
Emmeloord
Hotel Van der Valk Emmeloord
Het Hooiveld 9
8302 AE Emmeloord
Church by the Sea
Prins Hendrikstraat 1
8321 GG Urk
Former air watchtower Karel 1
Urk
Renne Regional Products
Domineesweg 11
8308 PG Nagele
Karwijhof 19
8308AK Nagele
Museum-Restaurant Schokland
Middelbuurt 3
8319 AB Schokland
PLEASE NOTE: as of mid-March 2026, the Keileemweg on Schokland will be closed to all traffic due to the poor road surface. Therefore, do not cycle south from the junction to cycle junction 75, but continue for a bit on the Oud-Emmeloorderweg and turn off at the first road on your right, the Plankenpad. This will lead you to cycle junction 61, the end of this route.
