A stoa (; plural, stoas,[1] stoai, or stoae [2]), in ancient Greek architecture, is a covered walkway or portico, commonly for public use. Early stoas were open at the entrance with columns, usually of the Doric order, lining the side of the building; they created a safe, enveloping, protective atmosphere.
This, an "open-fronted shelter with a lean-to roof", is the meaning in modern usage, but in fact the ancient Greeks "made no clear distinction in their speech" between these and large enclosed rooms with similar functions.[3]
Later examples were built as two storeys, and incorporated inner colonnades usually in the Ionic style, where shops or sometimes offices were located. These buildings were open to the public; merchants could sell their goods, artists could display their artwork, and religious gatherings could take place. Stoas usually surrounded the marketplaces or agora of large cities and were used as a framing device.[4]
Other examples were designed to create safe, protective atmospheres which combined useful inside and outside space. The name of the Stoic school of philosophy derives from "stoa".
See main article: List of stoae.