Cathedral Basilica of Saints Peter and Paul, Philadelphia

The Cathedral Basilica of Saints Peter and Paul is a key structure in the Roman Catholic Archdiocese of Philadelphia. Its construction spanned from 1846 to 1864 under the architectural guidance of Napoleon LeBrun, who built upon the original designs by Reverend Mariano Muller and Reverend John B. Tornatore. The cathedral's interior owes its elaborate decoration to the artistic prowess of Constantino Brumidi.

Architecturally, the Cathedral Basilica is a majestic sight. It is the largest brownstone building in Philadelphia and distinguishes itself with its remarkable architectural features. The cathedral can accommodate 2,000 worshippers within its vast sanctuary, which includes a vaulted dome, an ornate main altar, and eight side chapels.

The design of the cathedral is heavily influenced by Roman-Corinthian architecture, emulating the Lombard Church of Saint Charles in Rome. Its Palladian façade and aqua oxidized copper dome are inspired by the Italian Renaissance, a theme that continues in the spacious interior. This interior is notable for its oversized apse made of stained glass and red antique marble, proportions reminiscent of Roman churches. A distinctive feature is the Renaissance-style baldachin over the main altar, along with three altars in the side aisles, all influenced by Italian Renaissance design. The "Crypt of the Bishops" in the lower part of the building adds to its historical significance.

The Cathedral Basilica of Saints Peter and Paul was listed on the U.S. National Register of Historic Places in 1971 and hosted two papal Masses: one by Pope John Paul II in 1979 and another by Pope Francis in 2015.