A beach is an area of sand or gravel (more rarely silt) along the shore of a body of water. The sand is usually washed in from the ocean by waves and tides. Beaches may be found at sea, at lakes, or in rivers. A beach is often a popular recreation site where people swim, sunbathe, play games, build sandcastles, and watch the many species of marine life that live there.
Beaches are a dynamic landscape, changing from hour to hour and season to season. The size and shape of a beach depends on sediment drift, wave and wind actions, and the underlying geology. Beach sand is normally a very fine-grained, quartz-like material. Occasionally, beaches are covered with sand that is heavier and contains feldspars or minerals like gypsum. The sand at some beaches is even richer, containing bits of shell debris or the skeletons of marine organisms.
As the water in a surf zone washes over rocks and sand, it carries these grains up or down and back across a beach in a process called longshore drift. This is the primary reason that beaches change shape and form from day to day. Waves that are longer and more powerful are more likely to sweep up a beach, pushing the sand into a line along the coast. This sand line is called the beach ridge. The sand at a beach is also washed up into the surf zone by rip currents, which are powerful waves that break close to shore and push sand in a forward direction.
When these waves re-enter the beach from behind, they push down on the beach again. This sand is called backwash and can wash out to sea or, in some cases, be deposited offshore on a sandbank. Sandbanks are a common feature in estuaries and oceans and are sometimes called barrier islands.
In a calmer environment, beaches can develop sandbars, which are long, flat bars of sand and silt that extend into the water from the shoreline. These sandbars are generally formed in subtidal or intertidal zones. They reduce the energy of waves, protecting a beach from severe erosion and providing a place for marine vegetation to grow.
A beach may be covered with algae, sandpipers, crabs, shrimp, hermit crabs, and other creatures that live in the saltwater. At a beach that is near a river or stream, the water may be brackish and have different fish and plant species than at an ocean beach.
Beaches have been important recreational destinations for centuries, with their beautiful scenery, refreshing water, and fun activities. The emergence of railways and automobiles, as well as improved living standards, allowed many more people to access the coast. The popularity of the seaside resort increased and, by the late 1800s, a holiday home at the beach was seen as a mark of status among upper-class society. This trend was encouraged by the works of Jane Austen, including her unfinished novel Sanditon.