Editing Ancient Roman architecture (section)

=== Spiral stairs ===
{{further|List of ancient spiral stairs}}
The [[Stairway#Spiral and helical stairs|spiral stair]] is a type of [[stairway]] which, due to its complex [[helix|helical]] structure, was introduced relatively late into architecture. Although the oldest example dates to the 5th century BC,{{sfn|Beckmann|2002}} it was only in the wake of the influential design of [[Trajan's Column]] that this space-saving new type permanently caught hold in Roman architecture.{{sfn|Beckmann|2002|pp=353–356}}

Apart from the [[triumphal column]]s in the imperial cities of [[Rome]] and [[Constantinople]], other types of buildings such as [[Roman temple|temples]], [[thermae]], [[basilica]]s and tombs were also fitted with spiral stairways.{{sfn|Beckmann|2002|pp=353–356}} Their notable absence in the towers of the [[Aurelian Wall]] indicates that although used in [[medieval castle]]s, they did not yet figure prominently in [[Roman military engineering]].{{sfn|Beckmann|2002|pp=353–356}} By [[late antiquity]], separate stair towers were constructed adjacent to the main buildings, as in the [[Basilica of San Vitale]].

The construction of spiral stairs passed on both to [[Church architecture|Christian]] and [[Islamic architecture]].