This weekend marks the start of a trans-European race with a difference: Instead of the usual rally cars or racing bicycles, contestants must cross the continent using only public transit.

On Saturday, 180 racers will set off on from London’s Trafalgar Square on the second annual Race Across Europe, traveling on only trains, buses and ferries to the finish line in the Albanian capital some 1,200 miles away, Tirana. Organized by adventure travel agency Lupin Travel, the race is intended to test contestants’ ingenuity in both moving fast and thinking on their feet. Participants have to pass through four checkpoints on the way, but only the first of these, the Belgian city of Bruges, has been shared in advance.