Murals are large artworks executed as architectural features usually painted directly onto walls or ceilings. 

The most durable murals are fresco which is painted into damp plaster rendered onto walls and ceilings. The most famous are the murals by Michelangelo in the Vatican. This fresco technique takes a high level of skill and training and Michelangelo was fortunate that his early teacher was Ghirlandiaio who was the leading frescoist in Italy at the time. See: Fresco Murals