Toompea Castle, a historical and political landmark in Tallinn, Estonia, now home to the Estonian Parliament (Riigikogu), offers a fascinating visit. While its exterior and courtyard are freely accessible year-round for solo exploration, gaining insight into its parliamentary functions is best achieved through free guided tours of the Riigikogu, which often require advance booking and typically last 1-1.5 hours, though these might have seasonal availability or be restricted during parliamentary sessions and public holidays. The castle is situated on Toompea Hill, necessitating an uphill walk, but its immediate exterior and courtyard are generally accessible. For those not taking a tour, a typical visit to admire the exterior and the iconic Pikk Hermann tower, a national symbol, lasts around 30-60 minutes. It's recommended to combine the visit with other attractions on Toompea Hill for panoramic city views.