As an island nation with roughly 30,000 kilometers of coastline, Japan’s connection to the sea is as deep as the ocean itself.

This relationship is one of both of dependence, with most of the country’s population living in coastal areas, and fear, as tsunamis and storm surges periodically threaten communities.

A constant reminder of this complex interplay are the concrete structures that line more than 40% of Japan’s jagged coastline. From seawalls and embankments to wave-dissipating blocks and breakwaters, concrete has been used as the principal line of defense against the forces of the sea throughout the postwar period.