In the 1960s, 26 European countries removed controls at their borders, creating a zone known as the Schengen Area. This initiative to open the European borders resulted in a boom in not only tourism, but commerce as well. Traveling around Europe became as easy for Europeans, as passing between US states is for Americans. Unfortunately, this once great achievement now faces possible extinction due to growing security concerns following the recent terrorist attacks and refugee crisis in the region.

Previously, travelers have been able to travel throughout much of Europe without waiting in immigration lines or having their passports examined. Denmark and Sweden are some of the first countries to start cracking down on their border entry. The countries have imposed temporary identity checks for people entering Denmark from Sweden and vice versa for the first time in 50 years.

Travelers moving between the Swedish city of Malmo and the Danish city of Copenhagen on the 10-mile Oresund Bridge are now being asked to show a photo ID before being allowed over the bridge. Hours after the terrorist attacks in Paris, France imposed checkpoints between France and Belgium indefinitely and called for the implementation of border checks on all other roads entering France from Germany, Italy, Spain, and Switzerland.

Although these measures aren’t aimed at hindering leisure travelers, many travelers will likely feel the impact of such security measures at airports, train stations, sporting events. In addition, an enhanced law enforcement presence, may lead to potentially longer lines and more intense scrutiny of documents. A lot is currently still up in the air, as Europe determines how it will move forward implementing stricter border controls. One thing that is clear, is that Europe’s passport-free travel may not exist in the near future.