But that doesn't mean you should cancel your trip.
The U.S. state department has issued a travel alert notifying residents of the heightened risk of a terror attack during the Christmas season in Europe.
"While local governments continue counterterrorism operations, the Department remains concerned about the potential for future terrorist attacks," an excerpt from the alert reads.
The alert comes nearly a year after a truck rammed into a Christmas market in Berlin on December 19, 2016, killing 12 people and injuring dozens more. The Islamic State group, also known as ISIS, took responsibility for the attack.
Christmas markets in Germany and throughout Europe draw huge numbers of tourists and locals alike to sample and buy traditional goods each year. In the past, ISIS has encouraged its followers to carry out attacks at this time of year, given the large crowds that gather in outdoor events.
The state department alert warned travelers to be particularly vigilant when visiting so-called "soft targets," such as "hotels, clubs, restaurants, places of worship, parks, high-profile events, educational institutions, airports."
As the State Department notes, a travel alert is different from a travel warning, and it is not a reason to cancel a trip. Alerts are issued for everything from election periods, to influenza epidemics, to hurricane season. Warnings are more serious and are issued when the department aims to encourage travelers to seriously consider whether or not they should carry out their trip.
Concerned travelers can take additional precautions, such as putting an emergency plan in place and having the number of the local embassy on hand.
Europe remains safe and welcoming to visitors, and travelers can continue with their planned travel, according to the State department. The winter holiday season is still one of the best times to visit European cities, where the festive lights, Christmas concerts, and local markets draw travelers from around the world.
Whether in Paris, Berlin, or a small village somewhere in between, there is a reason why so many people choose to spend this special time of year in Europe.