Built between 1475-81, the Sistine Chapel is the private chapel of the pontiffs in Vatican City. It is used for papal ceremonies and for the conclave, when cardinals are locked in the chapel until they elect a new pope. Michelangelo painted his famous frescoes -- which feature nudes -- on the ceiling and the altar wall between 1508-41. During the 16th century, the Council of Trent ordered loincloths painted on the nudes, and over the next two centuries various Popes ordered other strategic touch-ups. When the Sistine Chapel was renovated, 17 of 40 figures were uncovered. Pope John Paul II approved. At his first mass in the renovated chapel he said, "The human body can remain nude and uncovered and preserve intact its splendor and its beauty."