Stoa

A stoa, 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 a 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.

Later examples were built as two storeys, and incorporated inner colonnades usually in the Ionic style, where shops or sometimes offices were located.