The main plaza in Cartagena is the beginning of the old city for most tourists. What you are seeing is the back drop of buildings in Plaza de la Aduana in Cartagena just near the famous clock tower. Cartagena is one of the most romantic cities in South America. It is already one of the most visited cities in Colombia and if the Colombian government ever got their act straight it could be one of the biggest in all of Latin America. Colorful buildings line the old city with balconies that are reminiscent of the old Spanish Empire. There is quite a bit of history in the city and also in the surrounding area so make sure to plan plenty of time on your trip.