National Geographic : 1939 Mar
Photograph by Branson De Cou MICHELANGELO DESIGNED THE MIGHTY DOME OF ST. PETER'S, LARGEST CHURCH INTHE WORLD Construction of the huge building, in the form of a Greek cross, was begun in 1506. Progress was interrupted several times and the form was changed toaLatin cross. The work was not completed for 120 years. The original structure which it replaced was erected by the Emperor Constantine sixteen centuries ago. Inthe center of the vast square on which the Basilica fronts stands an obelisk (left foreground) that once rose in the Emperor Nero's Circus.