The beautiful and majestic Vallø Slot(Vallø Castle) traces its history back to the 14th century. The building of the castle was finished in 1586 by Mette Rosenkrantz - one of the richest women of Denmark - with the addition of a west and south wing and the two characteristic towers. The other wings were built in the 17th and 18th century. The castle was devastated by fire in 1893 but restored largely to its old design between 1893 and 1904.

The estate was owned by well known noble families until 1708. In that year it was bought by King Frederik IV, who gave it to his mistress, later Queen Anne Sophie Reventlow. After his death the new King Christian VI gave Vallø Estate to his wife Sophie Magdalene. On her birthday in 1737 she established a foundation (‘Noble Vallø Foundation for Unmarried Daughters’), which turned the castle into a home for ‘spinsters of noble birth’. Unmarried daughters of Danish royalty, unable to live in their own castles, were allowed to live at Vallø, supported by the foundation and government social programs.

The castle still provides housing for women of the Danish nobility but since 1976 admission to the residences is not restricted to unmarried women but now also cover widows and divorced women.