An isthmus is a narrow strip of land connecting two larger landmasses, typically with water on either side. Think of it as a bridge of land between two bodies of water.
Here are some examples:
* The Isthmus of Panama: Connects North and South America.
* The Isthmus of Suez: Connects Africa and Asia.
* The Isthmus of Corinth: Connects the Peloponnese peninsula to mainland Greece.
The word "isthmus" comes from the Greek word "ισθμός" (isthmos), which means "neck" or "narrow passage."