For 10 points each, name these flat things with hinges that cover the entrances to buildings.
At Greene and Greene's Gamble House, this architectural feature is covered with a bonsai tree design. In order to encourage residents to avoid them, Frank Lloyd Wright tended to include very low ceilings around these features, which he often hid under shadowy overhangs. In Gothic buildings, these features could be paired around a trumeau. The 1883 Victoria Hall disaster led to the development of [*] crash bars, which are now affixed these features in most public buildings. Near the US Capitol Rotunda, Randolph Rogers designed an example of this feature whose carvings depict the life of Christopher Columbus. St. Mary's Cathedral in Hildesheim is home to an elaborate set of these objects named for Bishop Bernward, and ones called "The Gates of Paradise" adorn the Florence Baptistery. For 10 points each, name these flat things with hinges that cover the entrances to buildings. 
At Greene and Greene's Gamble House, this architectural feature is covered with a bonsai tree design.
doors