Want to see Titian's "Sacred and Profane Love"? Then you have to book your spot

For some of the best sights in Rome, you don't need to worry about reservations, or tickets, or a booking. You can waltz right into the Pantheon, explore Rome's lovely small churches, or gawk at Rome's archaeological treasures in the Palazzo Massimo without so much as a booking.

But some of Rome's coolest experiences do need to be planned in advance. How you'll get into the Colosseum or Sistine Chapel without standing in a 3-hour line, for example. (More on that in a future post). And some actually need to be booked.

Yes, you heard me. In the land of la dolce vita and 2-hour lunch breaks, there are tourist sights you can't get into unless you have a reservation.

And here they are.

St. Peter’s tomb

The necropolis under St. Peter’s Basilica—which includes what’s thought to be the tomb of St. Peter—makes a super-cool visit for anyone, not just pilgrims. The ancient tombs here are both pagan and Christian, many still with elaborate mosaic decoration; it gives you a great idea of what a 1^st-century, above-ground cemetery would have looked like.

But because the archaeological site is delicate, only 250 visitors can enter per day, on tours only, and must book in advance. Note that visitors also must be at least 15 years old.

To book, email scavi@fsp.va or fax +39 0669873017. You also can ask at the Excavations Office when you’re in Rome, but because these tours tend to book out weeks ahead of time, I wouldn't wait until then to do so. Make sure to include the number of participants, names, which language you need, how to contact you, and the period when you’re available to attend.

Borghese Gallery

The Borghese Gallery, which must be booked in advance

This is my favorite art museum in Rome, and it’s absolutely a must-see. To keep it a pleasant experience, however (and to protect the art), the museum limits the number of people who can be inside at any one time. Entrances are at 9am, 11am, 1pm, 3pm, and 5pm, daily except Monday. Book at least a week in advance in high season.

To book, either go to galleriaborghese.it and click on “Tickets reservations” or call +39 0632810. There is a €1.50 surcharge per ticket for booking online. You also can automatically get a reservation by booking a tour with a reputable tour company.

Palazzo Valentini

If the Borghese is my favorite art museum, this is my favorite ancient, underground site. (Although that sounds quite specific I can assure you that, in a city chock-full of them, it’s not!). Smack in the center of Rome, not far from the Forum, the 16^th-century palazzo sits on top of two opulent, ancient Roman villas. An (enthusiastic! and dramatic!) automated tour takes you through them as—drumroll, please—light shows “recreate” what they would have looked like.

You can book online at palazzovalentini.it (just make sure you pick an English, “inglese,” tour!). Or you can call +39 0632810, or make an appointment in person. However, particularly in high season or if you have limited time, I’d recommend booking this at least a week in advance.