Sandefjord is a small coastal town in Vestfold, about 120 km south of Oslo. It was once the whaling capital of Norway — the Hvalfangstmuseet (Whaling Museum) in the centre tells that story well — and the town still has a maritime character, with a harbour, marina, and pleasant waterfront.
For most visitors, Sandefjord is relevant because of Torp airport, which serves several budget airlines and is marketed as "Oslo Torp" despite being a good two hours from the capital by bus. If you are flying in, the town itself is worth a brief look: the Whaling Museum, the Viking burial mound at Gokstadhaugen (where the famous Gokstad ship was found), and the harbour area with its restaurants and summer atmosphere.
The Vestfold coast around Sandefjord has good beaches and small islands popular for kayaking and swimming in summer. Skjellvika is the most popular beach in the municipality, a sheltered lagoon on the eastern shore of the fjord, while Vesterøya peninsula offers rocky coastal scenery and quiet swimming spots.