A pier is a structure built out over water, usually supported by pillars driven into the sea floor or lake bed. Think of a long wooden walkway extending from the beach into the ocean, where people can walk out over the waves without getting wet.

Piers serve many purposes. Some are built for ships and boats to dock alongside, making it easier to load cargo or let passengers on and off. Fishing piers let anglers cast their lines into deeper water where bigger fish swim. Seaside resort towns often have pleasure piers with restaurants, shops, and even amusement park rides built right over the water.

In places like San Francisco or Seattle, old commercial piers that once bustled with ships unloading goods now host restaurants and museums.

A pier differs from a dock (which floats or sits at water level) and a wharf (which runs parallel to shore). A pier typically extends perpendicular to the shoreline, reaching out into the water like a finger pointing toward the horizon.