History of the world's tallest buildings
The tallest building in the world, as of 2022, is Burj Khalifa. The title of "world's tallest building" has been borne by various buildings, such as the Rouen Cathedral and the Empire State Building.
List of tallest buildings in Philadelphia
Philadelphia has twice held the tallest habitable building in North America, first with Christ Church, then with City Hall. The latter reigned as the world's tallest building from 1894 to 1908, and is currently the world's second-tallest masonry building, only shorter than Mole Antonelliana in Turin. Like other large American cities, Philadelphia went through a massive building boom in the 1970s and 1980s, resulting in the completion of over 20 high-rise buildings.