An arch that resembles a perfect semicircle and includes a "keystone" (or center piece) in the middle is an example of a Roman arch. Evolved from the Roman arch, a Gothic arch consists of two curved arcs that meet in a point at the top, giving it the ability to reach higher than the Roman arch.
Roman arches first appeared in Mesopotamia in the second millennium. Much later, Gothic arches were used during the medieval period.
Both arches are incredibly stable architectural feature, but because of the ability to create great height with a Gothic arch, flying buttresses are sometimes needed to provide additional support.
A prominent Gothic arch in history can be seen on the Notre Dame Cathedral in Paris. A typical Roman arch is seen in the Gateway Arch in St. Louis.
Among the first landmarks to use a Roman arch were palaces, temples, bridges, aqueducts and amphitheaters. Gothic arches were predominantly seen on churches and cathedrals, sometimes housing windows inside the archway.