Andújar is a Spanish municipality of 38,539 people (2005) in the province of Jaén, in Andalusia. The municipality is divided by the Guadalquivir River. The northern part of the municipality is where the Natural Park of the Sierra de Andújar is situated. To the south are agricultural fields and countryside. The city proper located on the right bank of the Guadalquivir and the Madrid-Córdoba railway. Andújar is widely known for its porous earthenware jars, called alcarrazas or botijos, which keep water cool in the hottest weather, and are manufactured from a whitish clay found in the neighbourhood.