Carlstad was a short lived fortified town in Denmark built by the forces of King Charles X Gustav of Sweden during his siege of the Danish capital, Copenhagen, 1658 - 1660. Carlstad's size rivalled the besieged Danish capital, reaching a peak of approx. 30,000 inhabitants. The modern Copenhagen district of Brønshøj, Bellahøj and Utterslev are located on or near the site. Several nearby streets are named for it; e.g. Svenskelejren (The Swedish Camp) and Skansebjerg (Trench Hill). The only preserved building extant at the time of the encampment is Brønshøj Church, used as a weapons store during the siege.