Enclosed within a protective wall reaching up to 20 metres in width, the Ciudad Amurallada (or Walled City) is Cartagena's old beating heart. Packed with well-preserved colonial buildings, it's a pleasure to stroll through; its streets of colourful low-rise merchant homes marked by iconic balconies are now mostly walked by either tourists or students who attend classes at the University of Cartagena during the day and linger for meals and nightlife after school is out. Cafes in Plaza Aduana and Plaza Santo Domingo teem with patrons, forging an incredibly jovial atmosphere; the districts of San Diego and El Centro are two not to be missed. There is plenty of food and shopping to be had, with a mixed bag of world-class restaurants and street food hawkers and the incredibly photogenic palenqueras — women dressed in vibrantly coloured clothing selling fruit in the streets — images of whom have become emblematic of Colombia as a travel destination.

The Ramona Town Hall is listed on the National Register of Historic Places. Built in 1894, it is one of the largest and oldest adobe structures still standing in southern California.

Alfonsino Castle, also known as Red Castle, is located on the Island of St. Andrew, at the port of Brindisi. This fortification dates back to 1481 and it was completed in 1492 by Ferdinand I of Aragon. It was built in defence of the city from possible sea attacks.