Romanesque architecture originated in medieval Europe between 1000-1200 AD. It is characterized by semi-circular arches and thick stone walls with few openings. Churches during this period had massive piers, groin vaults, and large towers to support their weight. Examples include Monreale Cathedral in Sicily with its two projecting towers and elaborate interior, Pisa Cathedral known for its leaning tower and columns cut from single stones, and Durham Cathedral in England notable for its pointed ribbed vaults and tall central tower.