Along the shore in Porsanger, Finnmark county (map below) you can see 2-3 meter high poles with small "fenced" platforms on top. They are placed there for the birds. These pictures were taken 21 May 2011.
Both the Oystercatcher and Mew Gull usually breed on the ground. The breeding success of such species is often correlated to the local predatory pressure. Obviously, a platform such as these makes the nest unaccessible for four legged predators, such as cats and minks. In addition they will not get any problems with high tides or waves visiting their nest. At least it seems they prefer platforms before the traditional ground in this area, possibly because of increased breeding success.