Fornebu is a rather flat peninsula in the Inner Oslofjord, indented by several narrow and shallow inlets, fringed with lush reed beds. The area has long been well-known for its rich and varied avifauna, and a bird observatory here was founded in 1969, now located in the old house Lilløyplassen. Fornebu is one of the best sites for finding resting migrants close to Oslo. Especially on mornings with overcast weather in spring, large numbers of pipits, thrushes and finches can migrate overhead or rest in the vegetation. On sunny days from late March to the end of May, it can be a good spot for watching migrating raptors and other soaring birds. Buzzard and large flocks of Cormorant may pass overhead early in this time-slot, followed by Roughlegged Buzzard, Hen Harrier, Crane and Pink-footed Goose, the latter two usually in flocks.