Cartagena is a port city on the Caribbean coast of Colombia. You’ll find by the sea the walled Old City, which was founded in the 16th century with plazas, cobblestone streets, and colorful colonial buildings. With a tropical weather, this city is also well known for its beautiful beaches. You can visit Isla de Barú, with its white-sand beaches and palm trees, and Islas del Rosario, famous for its coral reefs, by boat.