Torrid zone

For the geographical zone, see Tropics.
The Terrestrial Sphere of Crates of Mallus (c. 150 BCE), showing land masses in both the northern and southern hemispheres of the western hemisphere
Modern world map with the intertropical zone highlighted in crimson

The torrid zone was the name given by ancient Greek and Roman geographers to the equatorial area of the Earth, so hot that it was impenetrable. That notion became a deterrent for European explorers until the 15th century.