up Barrier or barrier in Wiktionary, the free dictionary. A barrier or barricade is a physical structure which blocks or impedes something. Barrier may...

Barrier islands are a coastal landform, a type of dune system and sand island, where an area of sand has been formed by wave and tidal action parallel...

The Great Barrier Reef is the world's largest coral reef system, composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 kilometres...

Israeli barrier may refer to: Israel–Gaza barrier Israeli West Bank barrier Israel–Egypt barrier This disambiguation page lists articles associated with...

The Gaza–Israel barrier (sometimes called the Iron Wall) is a border barrier located on the Israeli side of the Gaza–Israel border. Before the Israel–Hamas...

The sound barrier or sonic barrier is the large increase in aerodynamic drag and other undesirable effects experienced by an aircraft or other object when...

A flood barrier, surge barrier or storm surge barrier is a specific type of floodgate, designed to prevent a storm surge or spring tide from flooding...

The Thames Barrier is a retractable barrier system built to protect the floodplain of most of Greater London from exceptionally high tides and storm surges...

In constrained optimization, a field of mathematics, a barrier function is a continuous function whose value increases to infinity as its argument approaches...

The blood–brain barrier (BBB) is a highly selective semipermeable border of endothelial cells that regulates the transfer of solutes and chemicals between...