Where is the largest sea cave in the US?
Where is the largest sea cave in the US? Eleven miles north of Florence on U.S. Highway 101 are the remains of an ice-age beach of seafloor basalt, where waves hit fracture zones in the hard basalt to carve what is now Sea Lion Caves, the largest sea cave in the United States and one of the largest in the world.
What US state has the longest cave?
Planning a Visit? Mammoth Cave in Kentucky is the world's longest known cave system, with more than 400 miles explored, and one of the oldest tour attractions in North America.