A basilica is a type of building , usually a church, that is typically rectangular with a central nave and aisles, usually with a slightly raised platform and an apse at one or both ends. In Europe and the Americas it is the most common architectural style for churches though this building plan has become less dominant in new buildings since the later 20th century . Today the term basilica is often used to refer to any large, ornate church building , especially Roman Catholic and Eastern Orthodox, even if it does not strictly follow this style.
The basilican architectural style originated in ancient Rome and was originally used for public buildings where courts were held, as well as serving other official and public functions. The basilica was centrally located in every Roman town , usually adjacent to the main forum. As the Roman Empire adopted Christianity , the major church buildings were typically constructed with this style and thus it became popular throughout Europe .
Many older Roman Catholic basilicas are Catholic pilgrimage sites, receiving tens of millions of visitors per year. In December 2009 the Basilica of Our Lady of Guadalupe in Mexico City set a new record with 6.1 million pilgrims during Friday and Saturday for the anniversary of Our Lady of Guadalupe.