To fully admire the Casco Viejo’s defensive structure and to take a lovely walk while you’re at it, head to the approximately two-mile marine viaduct that encircles the Casco Viejo and forms part of the City’s famous coastal beltway, the Cinta Costera.
 
The marine viaduct opened in April 2014 and has a bike path, walking/jogging path, water fountains, viewing areas, and a plethora of flowers! As you walk, you will enjoy fantastic views of the Casco’s walls (which were so expensive, the Spanish King was rumored to have looked west and expressed his expectation to see the walls from Spain), the mother of pearl laden spires of the Cathedral, and the old military barracks among many other points of interest.

The marine viaduct was built primarily to help ease traffic in Panama City but has been quite controversial given that it interrupts the beautiful sea views from the Casco. Residents also feared it would impact the Casco’s World Heritage Site status (thankfully, it didn’t). To learn more about the controversy, see: http://archrecord.construction.com/news/2012/10/121022-Panama-City-Highway-Stirs-Controversy.asp
 
Despite the initial controversy, the Engineering News-Record recently awarded the third phase of the Cinta Costera, which includes the marine viaduct, the 2015 Global Best Project in Roads and Highway Award. For more information, see: http://www.marketwatch.com/story/engineering-news-record-selects-panamas-cinta-costera-3-for-best-road-and-highway-project-honor-2015-08-2 
 
How to get there: If you’re staying in the Casco Viejo, you can easily walk to the entrance. If you're driving,  you can park your car in the lot right after the roundabout en route to the Casco Viejo (flagged on the map below). If you take a taxi, you could ask to be dropped off at the Mercado de Mariscos (which is just a short walk away from the start of the viaduct) or at the parking lot indicated below.