The Campanian Amphitheatre stands at Santa Maria Capua Vetere, on the site of ancient Capua, one of the most important cities of southern Italy. Capua's prosperity drew on fertile land, roads, trade, and a long history predating Roman control. The great surviving amphitheatre belongs to the imperial period and replaced or succeeded an earlier arena nearby. That distinction matters because Spartacus's revolt began at a gladiatorial school in Capua in 73 BCE, long before the monumental building whose ruins dominate the site today.

The imperial amphitheatre was constructed and embellished through more than one campaign, with work associated with the Flavian period and later emperors including Hadrian and Antoninus Pius. Its enormous oval auditorium was carried on a complex system of arches, corridors, and stairways. Sculpted heads and architectural ornament decorated the exterior, while ranked seating arranged spectators around the arena. In scale it belonged among the largest amphitheatres of the Roman world, reflecting Capua's continuing civic ambition and the wealth available for elaborate public entertainment.

Beneath the arena, passages and chambers supported the movement of attendants, equipment, performers, and animals. Timber flooring and mechanical arrangements concealed these operations from the audience above. Gladiatorial contests and animal spectacles depended on trained specialists, suppliers, and coerced labor as well as the patrons who paid for them. The architecture made violent entertainment into a carefully managed public event. Capua's association with gladiatorial training gave this setting particular resonance, but stories about Spartacus should be connected to the earlier city's institutions rather than assigned directly to the later amphitheatre.

Late antique changes brought the end of the original spectacle culture, and warfare, abandonment, and reuse damaged the building. The movement of the principal settlement toward medieval Capua further altered the region. Stone from the amphitheatre entered later buildings, leaving the ruined structure as a quarry and landmark. Antiquarians recorded its remains before systematic excavation exposed the arena and underground spaces. Modern conservation has sought to stabilize the surviving walls while distinguishing ancient construction from the repairs necessary to make an enormous fragmentary complex accessible.

The archaeological site is interpreted together with nearby museums and other remains of ancient Capua, including evidence for gladiatorial culture and religious life. Conservation faces drainage problems, vegetation, structural instability, and the vulnerability of underground spaces. The amphitheatre is important both for its engineering and for the social system it reveals: imperial patronage, civic rivalry, spectatorship, professional performance, and exploitation were organized within one monumental enclosure. Its relationship with the earlier arena also demonstrates why a famous historical association must be separated from the actual chronology of the surviving masonry.