The cajon is a classic folk & pure "jug" instrument. (Jug instruments are instruments made from common, household, or work, supplies.) The first cajons were the simplest box drums. In Peru and box drums were used as early as the 16th century. Some of, if not, the first box drums were made from fish crates by African slaves. These served as replacement percussion for their native drums. Also, in Cuba, people have been transforming small dresser drawers into box drums for centuries. In time these jug instruments were refined and became an important part of Peruvian and Cuban music.
The top edges could be slapped against the box because they were often loose. A hole was cut in the side opposite the head, which allowed more sound to escape. To play the box, a player simply sat on it so that the striking surface was between his legs.
The cajon is most popular in Andean, Cuban, and Flamenco music, but it's down to earth, percussive qualities have become popular in various acoustic music settings. (www.artdrum.com)