The royal castle of Rosersberg (Rosersbergs Slott) and surrounding gardens. The best kept secret where time has stood still. The castle was built in the 1630s by the Oxenstierna family. It became royal in 1762, as the summer house of king Karl XIV Johan and queen Desideria. The castle is located fairly close to Stockholm and Arlanda airport, on the banks of lake Mälaren, in the municipality of Sigtuna.