The Early Bird gets the Last Supper

For which museums, monuments, and sights in Italy do you really need to reserve admission tickets ahead of time?

In the age of the Internet, many sights across Italy offer the opportunity to book your admisison tickets in advance for a set entry time...usually for a nice little booking fee of €1 to €5.

But are reserved tickets strictly necessary? Well, for many attractions, no. You can usually waltz up to the door and get right in—maybe you'll have to wait all of five minutes in line. In that case, I recommend you don't book ahead, as it can cramp your travel style, locking you into too many scheduled events and leaving little room for spontaneity. Plus, you can avoid paying that superfluous $2.

However, for a select few major museums and monuments, reserving an entry ticket ahead of time can save you a wait of one, two, or even three hours in line—well worth the paltry booking fee.

In some cases—especially if it's a sight that allows only a limited number of visitors in at a time—reserving ahead may make the difference between getting in and getting turned away at the door.

It's true; frequently I see people arrive at the ticket window only to discover that entry to see Leonardo da Vinci's Last Supper in Milan, or the Galleria Borghese in Rome, has already been sold out for the next two or three days.

Now, there are dozens of admissions you can book online, but here are the sights in Italy for which I truly recommend booking admission tickets before you leave (or at least a few days in advance from on the road).

Galleria Borghese (Limited admission; booking is obligatory, and though technically you could show up and "book" an entry for right then and there, in practice the museum truly is often fully sold out several days in advance. Since this is my favorite museum in Rome, I always pony up the usurious €5 booking fee in advance.)
» BOOK IT: tel. +39-06-32-810, www.ticketeria.it
» FULL STORY
The Colosseum (Otherwise the long lines mean you might have to wait for an hour or two; bonus: ticket includes the Palatine Hill.)
» BOOK IT: tel. +39-06-3996-7700, www.pierreci.it
» FULL STORY
Palazzo Massimo alla Terme (Limited, timed admission to the upper floor; if you book ahead, you won't have to "come back this afternoon" for the entry time you've been assigned.)
» BOOK IT: tel. +39-06-3996-7700, www.pierreci.it
» FULL STORY

Uffizi Galleries (You don't need to book ahead, but consider this: the line to get in can last literally one to two hours; advance ticket holders get to waltz right in—well, maybe you have to wait behind two or three others at the window to pick up your pre-booked tickets. If you already know what days you'll be in Florence, this is well, well worth the €3.)
» BOOK IT: tel. +39-055-294-883, www.firenzemusei.it
Accademia—Michelangelo's David (Again, you don't need to reserve tickets, but, again, the line can stretch down the block and last over an hour. Again, well worth the €3.)
» BOOK IT: tel. +39-055-294-883, www.firenzemusei.it

Leonardo Da Vinci's The Last Supper (Limited admissions; very often is sold out 2-3 days in advance. Seriously, don't risk showing up without a booking—unless you're for some reason going to be hanging around Milan for three or four days and can come back.)
» BOOK IT: tel. +39-02-8942-1146, www.cenacolovinciano.org

"Secret Itineraries" tour of the Doge's Palace (OK, booking this way ahead of time isn't strictly necessary, but there are only three tours a day in English—all in the morning: 9:55am, 10:45am, 11:35am—and they can sell out, so at the very least stop by the day before—or first thing the morning of—rather than risk just showing up at thee appointed time; or play it safe and book ahead.)
» BOOK IT: tel. +39-041-520-9070, www.museiciviciveneziani.it

The Leaning Tower (If you are really looking forward to climbing the Leaning Tower, you need to either show up at the crack of opening hours or book ahead—at least 15 days—since they're sold first-come, first-served and often sell out. Hint: to avoid waiting in the regular Leaning Tower line, while booking check the box to pick up your tickets either at the Central Ticket Office or the Museo delle Sinopie)
» BOOK IT: tel. +39-050-387-2210, www.opapisa.it

The Scrovegni Chapel (Annoyingly, they've started requiring advance reservations—at least one day in advance—at this jewelbox of a chapel covered inside with frescoes by Giotto—they also now rush you through in 15 minutes; I used to spend hours in this place, just studying the frescoes. Still, it's more than worth it.)
» BOOK IT: tel. +39-049-201-0020, www.cappelladegliscrovegni.it