Architecture, art or science of designing and building structures. While the beginnings of architecture are traceable to areas around the Nile, Euphrates, and Tigris rivers, the Greeks and Romans created the styles that we rely on today. Greek architecture used post-and-lintel construction: a rectangle formed by beams and columns. The Romans were the first to fully use the arch and to use concrete as a building material, making possible structures with enormous roof spans.
Byzantine architecture, which arose in the Eastern Roman Empire and later influenced Russia, introduced the dome. Islamic architecture featured interior courtyards surrounded by colonnades. At the end of the Middle Ages, European churches and monasteries were stoutly built, for defensive purposes. Starting at the end of the 12th century, stained glass, high pillars, and thin arches of Gothic architecture were held in equilibrium by exterior buttresses. The Renaissance brought a revival of classical (Greek and Roman) architecture. In the Baroque period, rich ornamentation and curves replaced the straight lines of the Renaissance. The 18th century saw a revival of classical architecture in Europe and America, and a Gothic revival began in the 19th century. Starting in the last half of the 19th century, the use of iron, steel, and reinforced concrete allowed skyscrapers to be built.