Holy Door

The Holy Door, also known as the Porta Sancta, is an entrance portal located in the Papal major basilicas in Rome that is traditionally sealed and opened during Jubilee years designated by the Pope. The doors are normally sealed with mortar and cement to prevent them from being opened, and are only opened during Jubilee years to allow pilgrims to gain plenary indulgences. The tradition of the Holy Door dates back to the 14th century and has been expanded by Pope Francis in 2015 to include local Holy Doors in Catholic dioceses around the world.learn more on wikipedia