Standing to the north of the large Stp109 Dusseldorf radar and observation complex is Wn109a Altona, a much smaller site featuring just a handful of bunkers.
Here you can find a series of Vf2a personnel shelters, a water storage reservoir, and the remains of a barracks block, along now close to the cliff edge and fenced off to the site of the coastal path.
The standout building here though is the R612 casemate – now sealed up and overgrown – and you can get an amazing view along the coast towards Calais from its embrasure.