The most enduring symbol of Puerto Rico is La Muralla. Nearly 400 years old, the city wall is composed of rock, rubble, and mortar that wraps around Old San Juan from the cruise-ship piers on San Juan Harbor to the capitol on the Atlantic Ocean. Its iconic sentry boxes serve as a symbol of the island’s Spanish heritage and resilience in an ever-changing world.
Experts have spent years studying the 16th-century methods used to build the structure in an attempt to recreate the magic mixture of sand, water, and limestone used to stucco the wall.Begun by Spanish colonists in the 1600s, the wall took 200 years to complete and has withstood multiple attacks by the English, the Dutch, and the Americans. But what proved nearly impenetrable to foreign attack has been rendered defenseless by modern life. Automobile traffic, pollution, and misguided attempts to preserve it have endangered the wall.
La Muralla, a nearly 400-year-old wall that surrounds Old San Juan. Photo © Suzanne Van Atten.
Forty-five feet wide and 40 feet high in some spots, La Muralla is crumbling in places. In 2004 a 70-foot section below the heavily traveled Calle Norzagaray fell, underscoring the urgency of stepping up preservation efforts. It wasn’t the first time the wall’s fragility was made apparent. A larger section fell into San Juan Bay in 1938, and in 1999, a Soviet oil tanker ran aground, damaging the wall’s northwest corner.
When the U.S. Army seized Puerto Rico in 1898, it took over maintenance of the wall and attempted its first preservation efforts. Concrete was used to patch La Muralla, but that only served to add weight to the wall and trap moisture inside it, which weakened the structure over time.
Now a National Historic Site, La Muralla is maintained by the National Park Service, which has been overseeing efforts to repair the wall. Experts have spent years studying the 16th-century methods used to build the structure in an attempt to recreate the magic mixture of sand, water, and limestone used to stucco the wall. Not only is the repair method they’ve developed more effective than concrete, it serves to preserve the wall’s historical integrity. The process has been used to repair the wall’s beloved sentry boxes. It’s a painstaking and costly process.
But La Muralla endures. Along with the fortresses of El Morro and San Cristóbal that adjoin it, the wall attracts 1.2 million visitors a year. Chances are, with the help of preservation efforts, it will continue to assert its soaring beauty and cultural significance as the proud protector of Old San Juan for years to come.
Excerpted from the Fourth Edition of Moon Puerto Rico.
