The first European to see the Dry Tortugas was Juan Ponce de León, who visited on June 21, 1513. Ponce de León caught 160 sea turtles there and subsequently referred to the islands as the "Tortugas" (turtles). They are called "Dry" owing to the absence of surface fresh water on the island. The archipelago includes a high concentration of historically significant shipwrecks dating from the 17th century to the present. The Dry Tortugas were a significant American naval base from colonial times to the early 20th century, providing a sheltered anchorage and coaling station through the Spanish–American War.