If you have just one day to visit Croatia, go to Dubrovnik. It is a beautiful city surrounded by city walls and fortresses. Once it was a powerful maritime and merchant City-republic. It had fleet of 200 ships that were trading all over the Mediterranean sea, going as far as America and India. It was also a center of cultural and scientific life. The first quarantine in the world was built in Dubrovnik in 1377. One of the oldest pharmacies in Europe was built in 1317, which is still open at same location. See more. Take a virtual walk on its walls.