Schloss Eggenberg, lying to the west of the city of Graz, was built in baroque style between 1625 and 1656 by the architect Pietro de Pomis by order of the Duke Hans Ulrich von Eggenberg (1568-1634).
The castle has many references to the new Gregorian calendar with 4 corner towers, representing the seasons, 365 windows in total representing the days of a year, 24 state rooms on the second floor representing the hours of the day, and several more.