Monte Carlo - Monaco, Palais du Prince

Yes, the sate apartments are open to the public for a 6 euros ticket, 3 if you bring children along. I presume they're mighty breathtaking, as the heritage of the Monaco royal family stretches back to the 13th century. Anyway, you can watch the changing of the guards for free at 11.55 am sharp, at the end of rue des Remparts.