Hvaler is an archipelago stretching southwards from Fredrikstad towards the border with Sweden. Some of the larger islands are interconnected with each other and the mainland through a series of bridges and an undersea tunnel. The myriad of small islands, low rocks, narrow straits and an underseas choral reef make excellent habitats for nesting Common Eider, Black Guillemot, gulls and terns. Most of the area is protected as Ytre Hvaler National Park. The main islands of Hvaler have a varied selection of habitats, from lush agricultural land, mixed forests, coastal meadows and dry, rocky hills with heather and pine woods. The latter is particularly good for Woodlark and Nightjar. Vikerkilen inlet with ajacent Vikertangen headland, is among the best sites for general birding on Hvaler.