St. Patrick’s Cathedral is one of the landmarks of Midtown Manhattan. Its Neo-Gothic aesthetic contrasts starkly with the Art Deco Rockefeller Center, thereby ensuring that no one walking on Fifth Avenue will miss its grandeur. The main part of the Cathedral was completed in 1878 and designed by architect James Renwick. St. Patrick’s Cathedral, which served as the sear of the Archdiocese of New York, has recently undergone a thorough renovation and appears to be sparkling like new. The next time you find yourself in Midtown, stop by St. Patrick’s and be impressed by these 10 facts about one of the City’s most famous Cathedrals.

10. St. Patrick’s Missing Cornerstone

On August 15, 1858, the cornerstone of St. Patrick’s Cathedral was laid by Archbishop John Hughes. The stone, which had been hewn by a 22-year-old Irish immigrant, was left open for two years so that New Yorkers could leave offerings in it. The cornerstone also contained “a parchment litany in Latin of ecclesiastical and government officialdom and a celebratory news report on the recent laying of the first Atlantic cable, heralding instantaneous communication with the continent from which so many of New York’s immigrant Catholics hailed.” It was sealed exactly two years later on August 15, 1860; then it went missing.

Today, no one knows exactly where the cornerstone is located and mysteriously the Archbishop John Hughes wrote that the cornerstone, “in all probability, will never be disturbed by human agency,” at the time it was sealed. The Cathedral considers it one of its greatest mysteries. According to some theories the cornerstone is long gone, according to others, it is still hiding along the Fifth Avenue facade of the Cathedral, at 50th Street.