Cartagena is a port city on the Caribbean coast of Colombia. By the sea is the walled Old City, which was founded in the 16th century, with squares, cobblestone streets, and colorful colonial buildings. With a tropical climate, the city is also a popular destination for its beaches. You can reach Barú Island, with its white sand beaches and palm trees, and the Rosario Islands, famous for their coral reefs, by boat. It is one of the most beautiful and best preserved cities in America.