Cathedrals, collegiate churches, and monastic churches like those of abbeys and priories, often have certain complex structural forms that are found less often in parish churches. They also tend to display a higher level of contemporary architectural style and the work of accomplished craftsmen, and occupy a status both ecclesiastical and social that an ordinary parish church rarely has. Such churches are generally among the finest buildings locally and a source of regional pride. Many are among the world's most renowned works of architecture. These include St Peter's Basilica, Notre-Dame de Paris, Cologne Cathedral, Salisbury Cathedral, Antwerp Cathedral, Prague Cathedral, Lincoln Cathedral, the Basilica of Saint-Denis, Santa Maria Maggiore, the Basilica of San Vitale, St Mark's Basilica, Westminster Abbey, Saint Basil's Cathedral, Antoni Gaudí's incomplete Sagrada Família and the ancient cathedral of Hagia Sophia in Istanbul, now a mosque.

Cologne Cathedral is a cathedral in Cologne, North Rhine-Westphalia belonging to the Catholic Church. It is the seat of the Archbishop of Cologne and of the administration of the Archdiocese of Cologne. It is a renowned monument of German Catholicism and Gothic architecture and was declared a World Heritage Site in 1996. It is Germany's most visited landmark, attracting an average of 6 million people a year. At 157 m (515 ft), the cathedral is the tallest twin-spired church in the world, the second tallest church in Europe after Ulm Minster, and the third tallest church of any kind in the world.