Panama, Isthmus of

the southeasternmost, narrowest part of Central America. The minimum width of the isthmus is 48 km. The term “Isthmus of Panama” is applied both to the entire country of Panama and to central Panama, the area between the Cordillera de Veraguas in the west and the Cordillera de San Blas in the east. In the second sense, most of the isthmus is a low-lying rolling plain composed mainly of volcanic rocks. The Caribbean side is covered with evergreen tropical forests, and savannas are found along the Gulf of Panama. The Panama Canal crosses the lowest part of the isthmus.