The Vadstena Castle is a Renaissance castle by Lake Vättern in the Swedish town of Vadstena (Östergötland, South Sweden), built starting in 1545 on the orders of King Gustavus I and completed around 1620.
It was a royal residence until 1716.Attualmente hosting the archive of the province (since 1899).
It is the best preserved Renaissance castle across Sweden.
The castle is located near the convent of Vadstena.
The castle stands on the lake Vättern and its walls are 30 meters in width and 3 meters in height.
However, many rooms are closed to the public.
The order to build the castle was given by King Gustav Vasa in 1544: the castle was to serve as a defense against attack from Denmark and the Småland and "replaced", in fact, the pre-existing XIII century, transformed into a convent in 1370 from Santa Brigida (1303-1373), to which the castle was donated in 1346 by King Magnus Eriksson. The construction work, especially of three buildings, began the following year.