The coast is the narrow strip where the sea meets the land.

Coasts may be made of steep cliffs with deep water offshore, or they may have beaches with sand or pebbles.

In some places the coast is made of headlands and bays. Usually steep cliffs and headlands tell of hard rock, whereas bays and beaches tell of softer rock at the coast.

Sand and pebbles all come from the waves breaking against cliffs. The constant breaking wears away the cliff at the waterline until it undercuts the cliff so much that the upper part of the cliff falls down. The broken rock is then worn down to sand and pebbles.

Most waves reach the beach at an angle, and so they push sand or pebbles up the beach at an angle, too. So every time a wave breaks, the sand is pushed a little way along the shore. This sand may build up in places to give long sandy beaches that stand out to sea. They are called spits.

Many people like to live by the coast, either because they work in ports, or they want to live in seaside places because they are on holiday or they have retired.

Some people live on soft rock cliffs that are easily worn away. This may not have been a sensible place to build, but a lot of effort and expense often goes into stopping these cliffs from wearing away any more. One of the most common ways is to put big fences into the beaches to trap sand. These fences (called groynes) make the sand form wide beaches. The waves break on the sand and use up all of their power before they reach the cliffs.