"The Rotunda of St Marija Assunta (sometimes shortened to Mosta Dome) is in Mosta, Malta and was designed by George Grongnet.

Its dome is among the largest in the world, with a diameter of 37 meters (122ft). Grongnet's plans were closely based on the Pantheon in Rome The building started in May 1833 and was not finished until the 1930s. The original church was left in place while the Rotunda was built around it allowing the local people to still have a place of worship while the new church was built. On April 9, 1942, during an afternoon air-raid, a 200kg Luftwaffe bomb pierced the dome (two others bounced off) and fell among the congregation of more than 300 people, awaiting early evening mass. It did not explode. Its replica is now on display inside the Rotunda"

From Wikipedia http://en.wikipedia.org/wiki/Rotunda_of_Mosta