According to About.com, the Tropic of Cancer is a line of latitude that runs through the Northern Hemisphere, 23.5 degrees north of the equator. Because it encircles the earth, the line also is found in the Eastern and Western Hemispheres.
Much of the Tropic of Cancer runs through oceans. It passes through Mexico, the Bahamas, Egypt, Saudi Arabia, India and southern China. Another important line of latitude is the Tropic of Capricorn in the Southern Hemisphere, found at 23.5 degrees south of the equator. The area of the earth between these two lines is a tropical region where the climate does not change significantly during the year.