buttress

A particularly fine example of the use of flying buttresses on the Gothic cathedral of Saint Barbara in Kutná Hora, Czech Republic. The building was financed by wealthy silver miners in the 14th century, who wanted to build a cathedral to rival St Vitus in Prague.

Detail of lattice-work and buttress in the Chapter House of the Monastery of Batalha, Portugal. The Dominican monastery - built to commemorate the victory of the Portuguese over the Castilians in the Battle of Aljubarrota in 1385 - represents the founding of Portuguese Gothic architecture typical of the 13th-15th centuries, with the new, more flamboyant trends of 15th-century architecture prevailing over the English influence. The monastery was designated a World Heritage site by UNESCO in 1983.

In architecture, a vertical mass of masonry that acts as a support or brace, projecting from the outer face of a wall at intervals. Its presence helps to resist the outward thrust of a vault, roof-truss, or girder. Buttresses were seldom used in classical architecture, and in Romanesque architecture were of slight bulk and projection. In the Gothic period they became increasingly larger, enabling the intervening wall to be reduced in thickness and to be pierced with large windows.

Types of buttress include the flying buttress, which arcs over a side aisle to support the heavy stone roof of a cathedral; and the pier buttress, which is simply a solid mass of stone.