Editing Colosseum (section)

=== Arena and hypogeum ===
[[File:0 Colosseum - Rome 111001 (2).JPG|thumb|The Colosseum arena, showing the ''[[hypogeum]]'' now filled with walls. The walls were added early in the Colosseum's existence when it was decided it would no longer be flooded and used for naval battles.]]
The arena itself was 83&nbsp;meters by 48&nbsp;meters (272&nbsp;ft by 157&nbsp;ft / 280 by 163&nbsp;Roman feet).<ref name="claridge"/> It comprised a wooden floor covered by sand (the Latin word for sand is ''harena'' or ''arena''), covering an elaborate underground structure called the ''[[hypogeum]]'' (literally meaning "underground"). The hypogeum was not part of the original construction but was ordered to be built by Emperor [[Domitian]]. Little now remains of the original arena floor, but the ''hypogeum'' is still clearly visible. It consisted of a two-level subterranean network of tunnels and cages beneath the arena where gladiators and animals were held before contests began. Eighty vertical shafts provided instant access to the arena for caged animals and scenery pieces concealed underneath; larger hinged platforms, called ''hegmata'', provided access for elephants and the like. It was restructured on numerous occasions; at least twelve different phases of construction can be seen.<ref name="claridge"/>

[[File:Panoramic photograph of interior of Colosseum.jpg|thumb|left|A view of the interior of the Colosseum; clearing showing the hypogeum (Greek for "underground")]]
The ''hypogeum'' was connected by tunnels to a number of points outside the Colosseum. Animals and performers were brought through the tunnel from nearby stables, with the gladiators' barracks at the [[Ludus Magnus]] to the east also being connected by tunnels. Separate tunnels were provided for the Emperor and the [[Vestal Virgins]] to permit them to enter and exit the Colosseum without needing to pass through the crowds.<ref name="claridge"/>

Substantial quantities of machinery also existed in the ''hypogeum''. Elevators and pulleys raised and lowered scenery and props, as well as lifting caged animals to the surface for release. There is evidence for the existence of major [[hydraulic]] mechanisms<ref name="claridge"/> and according to ancient accounts, it was possible to flood the arena rapidly, presumably via a connection to a nearby aqueduct. However, the construction of the hypogeum at Domitian's behest put an end to the practise of flooding, and thus also to naval battles, early in the Colosseum's existence. There is however wide debate over the practicality and logistics of this phenomenon which leads to speculation over its actuality. This is mostly because there is no physical evidence of naumachiae at the Colosseum remains.<ref>{{Cite web |title=The Ancient Romans Would Flood the Colosseum to re-enact sea battles |date=15 September 2016 |url=https://www.thevintagenews.com/2016/09/15/ancient-romans-flood-colosseum-re-enact-sea-battles/ }}</ref>