Hours: Grounds daily 8-1 hour before dusk. Visitor Centre daily 10-4, mid-May to early September; Sat.-Sun. noon-4, mid-Sept. to mid-Oct. Guided tours of the residence, lasting 45 minutes, are offered daily 10-4; reservations are required every day Nov.-Apr. and Mon.-Fri., early May-late June and early Sept.-Oct. 31. Visits without a tour are available daily 3-4:30, July-Aug. Sentries relief performed daily on the hour 9-5, late June-late Aug. No tours during official functions.