Ocean City, Maryland's, Boardwalk has seen a historic transformation through the years. Here's a special look at its long history.

Wooden and brush matwork jetties have been tried. They are better than walls, but still far from satisfactory, except under different conditions, in the Eads protection of the Mississippi.

From Ocean Beach to Uluwatu to Narrabeen, seawalls are promoted as the solution to beach erosion. Often they are the problem.

Seawalls have been banned in South Carolina since 1988, but miles of them were built before then.