The US nor’easter storm is nowhere near the Caribbean, yet its influence is rippling — literally — far and wide across the Atlantic. Huge waves are spreading out from the center of the storm, and they just arrived in Puerto Rico and the surrounding islands.

John Morales, a TV meteorologist in Florida who was raised in Puerto Rico, is calling it “one of the worst ocean swell events in recent decades,” and not just for Puerto Rico. Hispaniola and the Virgin Islands are getting smacked by these waves, too.

Andy Rivera, who runs the Puerto Rico Historic Building Drawings Society, agreed that these are the worst waves in decades. Rivera said Hurricane Maria didn’t affect Old San Juan as much as it did the other parts of Puerto Rico. But the hurricane made the historical town “softer” — in other words, Maria made Old San Juan more susceptible to damage from waves like these, or even everyday storms.

“The ocean swell event has been so impactful in the Caribbean,” Morales wrote on Twitter, “that even within San Juan Bay the rising water and wave action caused damage along the outside of ancient wall surrounds Old San Juan.”

Old San Juan is the oldest settlement in Puerto Rico. San Juan is the oldest city in the United States, founded in 1521. Puerto Rico has a lot of history — and it has been through plenty of storms.

On Monday, the same nor’easter that battered the New England coast managed to do more damage to San Juan than many of the hurricanes it has faced over the centuries.

Across the northern shore of Puerto Rico, waves were crashing onto beaches and flooding coastal roads. Huge waves pounded Old San Juan on Monday morning, damaging some historical landmarks, including Paseo de la Princesa, a roadway turned promenade around Old San Juan that is popular for its food vendors and artist stalls.

The waves are expected to last into at least Tuesday, according to the Ocean Prediction Center.