It is 6 kilometres (3.7 mi) east of the centre of the city of Sandefjord, and immediately south of the Årø peninsula.

Attractions on the island include Sandbukta ("sand bay"), which is a beach on its eastern side.

It is also a common destination for recreational activities such as camping, paddling, sea trout fishing, hiking, and sailing.

[1] The island hosts annual summer camps for the Queer Youth Festival and the YWCA-YMCA Guides and Scouts of Norway.

[9] The name Natholmen ("night islet") derives from the older days when the island was used overnight for local fishermen.

In the early 1600s, the island was a loading site for Dutch ships that arrived to purchase lumber.

The organization purchased the farm and opened the campground "Knattholmen Leirsted & Kystleirskole" in August of the same year.