Nothing ruins a city trip faster than an endless queue outside a monument. One to two hours standing in the sun is half a day gone. The good news: with a few simple reflexes, you avoid most of these queues. Here's our method.

Book your skip-the-line tickets online

By far the most effective tip. For the most popular sites, the Colosseum and Vatican in Rome, the Eiffel Tower and Louvre in Paris, the Sagrada Família in Barcelona, a dated, timed ticket lets you in through a dedicated line, often within minutes. Book several days ahead: slots sell out fast in high season.

Visit early morning or late in the day

Crowds follow a predictable rhythm: they arrive mid-morning and leave mid-afternoon. Be there at opening (or in the last slot) and you'll enjoy the sites almost empty, in often lovelier light. Bonus: the heat is more bearable at off-peak hours.

Target the quiet days

Weekends and Mondays (when many museums close, shifting the load onto the others) are the busiest. Favour mid-week. Also check the free-entry days: they draw huge crowds, so it's better to book a slot anyway.

Consider a guided tour or a city pass

A guided tour almost always includes priority access, you save time and gain context. City passes (often skip-the-line) can also pay off if you chain several sites. Weigh it up against your programme.

For each destination, the CityPlanner app shows you the must-sees, the best visiting times and the activities to book, for a queue-free stay.

Prepare your visit with the CityPlanner app