An isthmus is a narrow strip of land that connects two larger bodies of land. An isthmus generally has water on both sides.
Another type of isthmus, called a tombolo, features a strip of land that is a spit or a bar, and it normally joins an island to the mainland.
An isthmus is a type of land formation in which canals are frequently cut as a way to provide a shortcut for marine transport. The Panama Canal is built across the Isthmus of Panama and connects the Atlantic and Pacific oceans. The Mediterranean Sea and the Indian Oceans are connected by the Suez Canal, which runs across an isthmus extending from the Sinai Peninsula.