• An isthmus is a narrow strip of land that connects two larger landmasses and separates two bodies of water. 
    Isthmuses have been strategic locations for centuries. They are natural sites for ports and canals linking terrestrial and aquatic trade routes. Isthmuses are also key sites for communications and cultural exchange, as well as military outposts.
    The Isthmus of Panama in Panama links the continents of North and South America, and separates the Pacific and Atlantic Oceans. The Panama Canal stretches 77 kilometers (48 miles) across the isthmus, and allows cargo ships to travel from eastern North America to western North America without having to go around South America. The Panama Canal revolutionized shipping and travel in the 20th century, allowing for faster and more efficient transportation of goods and people.
    The Isthmus of Suez in eastern Egypt connects the continents of Africa and Asia, and separates the Mediterranean and Red Seas. The Suez Canal is 192 kilometers (119 miles) long and allows cargo ships to travel between Europe, North Africa, western Asia (via the Mediterranean Sea in the north) and eastern and southern Asia without having to go around Africa. The Suez Canal facilitated trade and travel in the 19th century, and continues to define the oil trade today.
    The city of Seattle, Washington, is located on an isthmus between the Puget Sound (part of the Pacific Ocean) and Lake Washington. The region has been continuously inhabited for more than 4,000 years. The earliest settlers of the area were the Duabish, who settled near the ocean, and the Hachuabish, who settled near the freshwater lake. European settlers, who quickly saw the isthmus' potential for trade along the west coast of North America as well as across the Pacific, collectively referred to these Native Americans as the Duwamish.
    Tombolos are a type of isthmus. A tombolo forms as tides and waves create a thin strip of land between a coastal island and the mainland. The island connected to the mainland in a tombolo is called a tied island. (The built-up sandbar "ties" the island to the mainland.)
    Mount Maunganui, New Zealand, is a tombolo town located on a sandbar connecting the volcanic island of Mauao to the mainland. Mauao is an extinct volcano, and is a popular spot for hiking and sightseeing the local beaches. Those beaches offer diverse opportunities due to the tombolo formation. Beaches on the side of Mount Maunganui's isthmus facing Tauranga Harbor are calm and protected. Beaches on the other side of Mount Maunganui face the open ocean (the Pacific), with dramatic waves that are popular with surfers.
    Perhaps the most famous tombolo is the Rock of Gibraltar, a tied island narrowly connected to the southwestern tip of Europe's Iberian Peninsula. The Rock of Gibraltar is the northern part of the "Pillars of Hercules," which form the narrow western entrance to the Mediterranean Sea. This strategic location has made the Rock of Gibraltar a key site for traders and explorers since the Phoenicians. Today, the Rock of Gibraltar borders Spain, but is part of the British territory of Gibraltar.
    Storms may make isthmuses like this one dangerous places to live.

    Passing Through
    It takes ships about 8-10 hours to cross the Isthmus of Panama through the Panama Canal. About 14,000 ships make the crossing between the Atlantic and Pacific Oceans every year.

  • Term Part of Speech Definition Encyclopedic Entry
    aquatic Adjective

    having to do with water.

    beach Noun

    narrow strip of land that lies along a body of water.

    Encyclopedic Entry: beach
    border Verb

    to exist on the edge of a boundary.

    canal Noun

    artificial waterway.

    cargo Noun

    goods carried by a ship, plane, or other vehicle.

    city Noun

    large settlement with a high population density.

    coast Noun

    edge of land along the sea or other large body of water.

    Encyclopedic Entry: coast
    collective Adjective

    combined or unified.

    communication Noun

    sharing of information and ideas.

    continent Noun

    one of the seven main land masses on Earth.

    Encyclopedic Entry: continent
    define Verb

    to identify or associate with.

    diverse Adjective

    varied or having many different types.

    efficient Adjective

    performing a task with skill and minimal waste.

    extinct volcano Noun

    volcano that will no longer erupt.

    facilitate Verb

    to help or make easier.

    harbor Noun

    part of a body of water deep enough for ships to dock.

    Encyclopedic Entry: harbor
    inhabit Verb

    to live in a specific place.

    isthmus Noun

    narrow strip of land connecting two larger land masses.

    Encyclopedic Entry: isthmus
    landmass Noun

    large area of land.

    military Noun

    armed forces.

    ocean Noun

    large body of salt water that covers most of the Earth.

    Encyclopedic Entry: ocean
    oil Noun

    fossil fuel formed from the remains of marine plants and animals. Also known as petroleum or crude oil.

    open ocean Noun

    area of the ocean that does not border land.

    outpost Noun

    settlement or station located in a remote area.

    peninsula Noun

    piece of land jutting into a body of water.

    Encyclopedic Entry: peninsula
    port Noun

    place on a body of water where ships can tie up or dock and load and unload cargo.

    Encyclopedic Entry: port
    potential Noun


    region Noun

    any area on Earth with one or more common characteristics. Regions are the basic units of geography.

    Encyclopedic Entry: region
    revolutionize Verb

    to completely change a process or way of doing something.

    sandbar Noun

    underwater or low-lying mound of sand formed by tides, waves, or currents.

    sea Noun

    large part of the ocean enclosed or partly enclosed by land.

    Encyclopedic Entry: sea
    settler Noun

    person who migrates and establishes a residence in a largely unpopulated area.

    shipping Noun

    transportation of goods, usually by large boat.

    site Noun

    specific place where something is located.

    sound Noun

    body of water, larger than a bay, partially surrounded by land.

    strategic Adjective

    important part of a place or plan.

    terrestrial Adjective

    having to do with the Earth or dry land.

    territory Noun

    land an animal, human, or government protects from intruders.

    tide Noun

    rise and fall of the ocean's waters, caused by the gravitational pull of the moon and sun.

    Encyclopedic Entry: tide
    tied island Noun

    island permanently linked to the mainland through a narrow strip of sand built up through the action of waves and tides.

    tombolo Noun

    coastal landform created as waves and tides create a narrow, permanent isthmus between a coastal island and the mainland.

    trade route Noun

    path followed by merchants or explorers to exchange goods and services.

    transportation Noun

    movement of people or goods from one place to another.

    volcanic island Noun

    land formed by a volcano rising from the ocean floor.

    wave Noun

    moving swell on the surface of water.