Gothic cathedrals
The vaults were made of ribs which met each other at the highest part of the vault. In between the ribs were sloping surfaces of stone or brick that could be much thinner and lighter than the ribs. At first the pattern made by the ribs was quite plain, like Romanesque vaults, but architects, particularly in England, soon started adding small ribs in between the main ones and making different patterns. Some vaults like this can also be seen in Spain and Germany, but not usually in France or Italy.