Pantheon, Rome, Italy
Pantheon located in the Piazza della Rotonda in Rome, Italy, was originally built as a Roman Temple. Later it was consecrated as a Roman Catholic Church named Chiesa di Santa Maria dei Martiri (the Church of St. Mary and the Martyrs).
Giant concrete dome with a central opening (oculus) named the Great Eye is 43,3 meters (142 feet) in diameter and is the largest masonry dome in the world. The dome gets thinner as it approaches the Great Eye at the top of the dome with a diameter of 8,7 m (29 feet). Dome's diameter is equal to its height from the floor. The portico is supported by three rows of eight 14 meters (46 feet) high granite Corinthian columns.

Tyn Church, Prague, Czech, Republic
Tyn Church or the Church of Our Lady before the Tyn is a Roman Catholic Church located in the Old Town district of Prague, Czech Republic. The first Romanesque Church of Our Lady before the Tyn was built about 1185 but the construction of the present Gothic church began about 1360 and was not completed until 1470.
The Church of Our Lady before the Tyn was renovated between 1876 and 1895. Modern restoration of the exterior was carried out between 1973 and 1995 but the interior restoration is continuing.
Rotunda of Mosta, Malta
The Rotunda of Mosta or Mosta Dome is a Roman Catholic Church located in the city of Mosta, Malta. The Rotunda which is dedicated to the Assumption of the Virgin Mary was built between 1833 and 1860 over and around a church from 1614.The Classical style design for the massive church which can receive about 12,000 people was made by Maltese architect Girogio Grongnet. Grongnet's design resembles the Pantheon in Rome, while church's massive dome with a diameter of 37 meters (122 feet) is one of the largest on the world.
Rotunda was hit by a German 200 kg bomb during World War II in 1942. The bomb pierced the dome and fell among the congregation of 300 people awaiting early evening mass. Fortunately the bomb did not explode and nobody was hurt. The event became legendary and a replica of the German bomb is displayed in sacristy in commemoration.