Cruise lines are providing exclusive admittance to museums and cultural sites around the globe. New this year, Silversea Cruises’ Silver Cloud takes you behind the scenes of the Monte Carlo ballet with a former dancer. You can see the company’s costumes, some designed by Matisse and Karl Lagerfeld; watch the making of pointe shoes, or observe ballerinas as they train (seven-day cruises from Rome to Barcelona from $4,118 per person; tours from $189 per person). This month, Crystal Cruises’ Crystal Serenity offers a private, after-hours tour of the Vatican Museum and the Sistine Chapel (888/722-0021; crystalcruises.com; nine-day cruises from Venice to Monte Carlo from $5,045 per person; tours from $769 per person). And on Abercrombie & Kent’s Egyptian cruises on the Sun Boat IV, you’ll get to visit the Egyptian Museum before opening hours and tour the tomb of Seti I, in the Valley of Kings, which is otherwise off-limits (800/554-7016; abercrombiekent.com; 11-day cruises round-trip from Cairo from $6,575 per person, tour included).