This collection contains 15 high quality churches from all over the world of Christianity.

A cathedral is a Christian church which contains the seat of a bishop, thus serving as the central church of a diocese, conference, or episcopate. The counterpart term for such a church in German is Dom from Latin domus ecclesiae or domus episcopalis; also Italian Duomo, Dutch Domkerk and cognates in many other European languages. Churches with the function of cathedral are usually specific to those Christian denominations with an episcopal hierarchy, such as the Roman Catholic, Anglican, Orthodox, and some Lutheran and Methodist churches. Church buildings embodying the functions of a cathedral first appeared in Italy, Gaul, Spain and North Africa in the 4th century, but cathedrals did not become universal within the Western Catholic Church until the 12th century, by which time they had developed architectural forms, institutional structures and legal identities distinct from parish churches, monastic churches and episcopal residences.