Between October 2022 and March 2026, a significant preservation and enhancement project of the Colosseum took place.

• The Project

  From the western entrance (the Porta Triumphalis, integrated by Valadier’s 1826 restoration) and from arch LX, which you can see marked on the ground – and up to the so-called Stern Buttress, corresponding to arch XVIII, two important activities were carried out:

  • an archaeological excavation across the entire area covering approximately 3,000 square metres of surface
  • the laying of new paving, in the space left empty by the two missing rings of the Colosseum’s perimeter, in travertine slabs, interrupted by the outlines of the pillars that originally supported the vaults of the collapsed corridors.

  The original perimeter of the Colosseum is preserved in its entirety only in the northern sector, facing Via dei Fori Imperiali.

  On the southern sector, facing the Celio Hill, the perimeter completely lacks two ambulatories, whose framework was composed of pillars and vaults and whose height was nearly 50 metres, as in the northern sector.

  The void created by the collapse of this imposing structure, which began as early as the 6th-7th century due to earthquakes and natural subsidence also caused by the abandonment of the amphitheatre, left only rubble on the ground which in subsequent centuries was in turn excavated to recover building material, creating further voids filled with the materials in use during those same centuries, in a succession of voids, solids, reuses and refunctionalisations that have continued to the present day.

• The Construction System of the Colosseum

  The sector of the Colosseum corresponding to arches LXII-LXVI has been deliberately left exposed. The purpose of this choice is twofold:

  • to leave visible the difference in level compared to the walkway floor, a difference that corresponds to the thickness of the original paving, consisting of massive travertine blocks, nearly 1 metre thick (approximately 90 cm), laid flat and on edge.
  • to leave visible the impressions left on the preparation surface by the weight of these blocks, once they were “robbed” to be reused from the Middle Ages onwards for the new buildings of Christian and Renaissance Rome.

  The traces left by these blocks allow us to understand how the Flavian Amphitheatre was designed and constructed:

  • once the foundation slab was completed and the spaces for the drainage system were set aside, the blocks for the bases of the pillars supporting the vaults were put in place, positioning travertine parallelepipeds approximately 0.90 m high. These blocks left well-marked impressions, up to 10 cm deep, with smooth and horizontal surfaces.
  • Around the perimeter of the bases, the blocks of the ambulatory paving were laid directly on the foundation surface, both end-on and on edge.
  • In the spaces spared by this arrangement, on the passage of the ambulatories not occupied by the radial channels, structural platforms were provided, built in mortar of lime and red pozzolana, of rather tenacious consistency. The platforms served to fill the voids left by the load-bearing structures and probably were meant to facilitate the construction of the paving in points where the load was null. These platforms, approximately 40 cm thick, were to be covered with paving made of travertine parallelepipeds half as thick as those used in other sectors, namely approximately 45 cm.

• The Foundation of the Colosseum – Preservation

  The excavations brought to light the layer of mortar spread in antiquity above the monument’s foundation to accommodate the paving in travertine blocks. This mortar preserves clearly visible impressions of the paving blocks removed over the centuries. This is not mortar designed to be exposed, but only to accommodate the travertine blocks of the paving. In some cases, the layer consisted of heaps of travertine chips: these are very delicate and perishable materials based on lime putty with little travertine dust and pozzolana. Due to their fragility and to avoid damaging them, these layers were analysed, restored and covered to prevent their deterioration. Only a small stretch of this paving preparation has been left exposed; however, this choice requires continuous maintenance precisely because these materials deteriorate easily when subjected to atmospheric agents, not being intended, even in antiquity, to be exposed.

• Commodus's Passage

  Arch V of the Flavian Amphitheatre conceals a passageway used exclusively by the Emperor to access privately and appear on the arena, impressing the audience of spectators seated in the cavea.
  The so-called Commodus Passage (named after the Emperor that sources describe as a great enthusiast of gladiatorial spectacles) was reopened to the public in October 2025 and is open to visitors and can be visited with a special ticket, which can be booked here.

  It was a vaulted corridor, created probably at Domitian’s time by excavating within the robust foundations of the Amphitheatre when the building had already been completed. The vault was interrupted by wide trapezoidal windows called “wolf mouths” (bocche di lupo), which ensured light and air to the underground passage. During the refurbishment works of this portion of the building, the Colosseum Archaeological Park team deliberately left part of the corridor’s vault exposed and restored some of the” wolf mouths” with a glass pane: if you approach and look inside, you might perhaps imagine the emperor walking to approach the spectacle arena.

• The New Paving, the Crepidoma and the Arch Numbers

  The new paving, besides guaranteeing accessibility to all visitors, including those with mobility difficulties through ramps, was created with the intent of delineating the lost perimeter of the Amphitheatre whose image had been modified over the centuries.

  Starting from the blocks remaining in situ in other sectors of the Colosseum, the southern sector paving was designed in travertine slabs that recalls its great original dimension, delimiting the few original fragments that survived. Where once the powerful travertine pillars that supported the 50 metres of the building stood, raised travertine elements have been positioned which, in stylised form, allows to evoke the sequence of radial and annular ambulatories.

  Where once stood the numbered arches that punctuated the façade and allowed spectators to reach their sector, the arch numbers have been carved on the floor.

  An important element for defining the perimeter and for conveying the impression that the amphitheatre must have had in its original narrow valley is the restoration of the crepidoma steps, which delineated and raised the building from the respect area, also paved in travertine blocks. The respect area can be identified both in the north-eastern sector, where the travertine boundary stones that delimited it are visible, and in front of arches VI to XVIII.

  During the excavation activity, the brick delimitation of the foundation also emerged, approximately 1.5 metres from the crepidoma; in one stretch it has been marked with precise metal elements indicating its perimeter.