The Colosseo/Fori
Imperiali
Station

Construction

Prior to the construction of the diaphragm walls, it was necessary, given the particular context of the structure, to create a series of piles and micro-piles for the excavation of the Clivo di Acilio and the Clivo di Venere Felice. In particular, 900 micro-piles with 2 or 3 levels of tie rods were constructed on the north side of the construction site (Clivo di Acilio side), and 150 large-diameter piles were constructed on the south side (Clivo di Venere Felice side).
At the platform level, specifically at the odd track (Clivo di Acilio side), the construction of 2 galleries is planned using the traditional excavation method – extending from the TBM. These galleries – excavated in both the Amba Aradam and Venezia directions relative to the station structure – will be built under a hydraulic head of approximately 20 m after the surrounding soil is consolidated through radial injections performed from inside the TBM.

The station structure serves as an important interchange node with the existing Colosseo station on Line B. To allow the underground connection between the atrium level of Line C and the platform level of Line B, an underground bridge was constructed. This bridge spans over the tracks of the existing Colosseo station on Line B, effectively ensuring seamless access to the metro network. Through a connecting tunnel, passengers from the atrium level of Line C can access the Colosseo station platform on Line B, in both the direction of Termini and Laurentina.

End benefit and sustainability

The Fori Imperiali station serves as an important interchange node between Line C and Line B, enhancing the network effect for the entire Rome Metro network and effectively improving public transportation in the capital. The construction of the Fori Imperiali station has provided a valuable opportunity to document new stratigraphic excavations extensively and reveal the archaeological remains still present underground, downstream of the excavations related to the construction of the Via dell’Impero during the fascist era.

Clivo di Acilio: Preliminary archaeological interventions were initially carried out before constructing the pilework supporting the Velia along the northern boundary of the station, along the Clivo di Acilio and in the gardens of Villa Rivaldi. Later, it became necessary to remove part of the architectural layout designed by Antonio Muñoz, exposing the stratigraphies and structures spared by the cutting of the Velia and preserved behind the containment wall. These structures were related to residential buildings that occupied the southeastern slope of the hill during the imperial era. Below the layers of backfill from the early modern period, starting from an elevation of about 32.00 meters above sea level, the remains of a complex of structures dating from various building phases, spanning from the early imperial era to late antiquity, emerged. These structures were arranged on terraces sloping in an east/southeast direction and were probably accessible from the ancient road, which corresponds to the current Via del Colosseo.

Clivo di Venere Felice / Piazzale del Colosseo: Excavations for the construction of the tunnel connecting the Colosseo station on Line B with the Fori Imperiali station on Line C exposed the surviving portions of buildings dating from the late republican period to the early imperial era in this sector. The most significant find in this area was a monumental structure consisting of a large circular structure (with a diameter of 14 meters), likely a fountain, surrounded by residual rooms that served as a connection to a rectangular basin with marble lining located just to the south. This monumental complex, dating to the Flavian era as a whole, was not known in archaeological literature. Although most of it is preserved only at the foundation level, its discovery enriches our knowledge of the architectural arrangement in the northwestern part of the piazza of the Amphitheatre.

Excavations inside the station structure: This sector is located at the summit of the Velia, originally situated at an elevation of 43 meters above sea level. The bottom level of the excavation for the construction of Via dell’Impero reached an elevation of about 22 meters above sea level in 1931. A large section of the gardens of Villa Rivaldi and the significant multi-stratified archaeological complexes preserved underground and partly incorporated into the structures of the Villa, only documented hastily during excavation, were completely removed. Among the few archaeological remains that survived the excavation, the surviving portions of the wells for capturing groundwater, generically referred to as “archaic,” play a significant role. These wells reach deep into the Pleistocene loam-sand deposits.

Excavations in Well Q18: The construction of the Fori Imperiali station involved works of interconnection between Line C and Line B, including the connecting corridor, the overpass structure of the existing gallery, and the well known as Q18, which will provide access to the platform towards Termini. Despite the limited extent of the investigated area, the data collected during the excavation of Well Q18 bear witness to a highly complex archaeological panorama, characterized by intense construction activity that, starting from the late Republican period, led to the progressive transformation and monumentalization of the valley until the construction of the Flavian Amphitheatre.

The buildings that have come to light, referred to as Building 1 and Building 2, though only partially explored, represent a significant snapshot of the layout of the lower slopes of the Oppian Hill in the late Republican period, an area previously little known north of the Colosseum. In both cases, they appear to be residential complexes, organized on descending levels that follow the natural slope. The oldest evidence of the construction sequence is represented by Building 1, with reticulated masonry and rubricated conglomerate floors.

These massive structures, built against the earth on the north and east sides, also served as retaining walls for geological deposits and descended southward toward the valley floor. The rooms in the northern part of the investigated area (Building 2) were likely constructed later than the first building. This architectural complex differs from the previous one in terms of construction techniques, as it makes use of tegulae fractae. Room A6, with a central plan, has been interpreted as a laconicum due to the presence of a central circular masonry element, a probable support for a brazier. The adjacent room to the south (Room A5) was transformed into a basin at a later stage than the initial construction. To the east, there were two rooms with opus sectile and mosaic floors (A4 and A7) and a small underground room with access stairs made of travertine blocks. The elevation of the finished floor of the room, which was removed in ancient times but can be deduced from the profile of the structures, especially from the lower limit of the white plaster wall covering, was probably located at 21.75 meters above sea level.

The Strategy

The general strategy involves defining two complementary and dialectical terms: one space as a background and a system of precious and eloquent presences tasked with narrating archaeology:

• The cavity of the station is a space in semi-darkness, with a neutral but impactful character in terms of materiality to evoke the physicality and darkness of the matter it has penetrated;
• In the semi-darkness, spatial episodes stand out like precious objects at the bottom of a well. They are intended to tell the story of archaeology and serve as a preparatory function for the visiting experience and use of the most significant archaeological area in the world, just below the surface. A station is not a museum and retains characteristics and prerogatives that require space management focused on safety and the functionality of significant public flows driven by efficient transportation purposes. For this reason, the archaeological narrative takes on the role of precise writing that brings to life and characterizes, with its uniqueness, the succession of station environments.

The Narrative

The guiding narrative is based on these three elements, with moments of historical/archaeological communication seen as luminous gems immersed in the dark material of the underground space. Based on this framework, the spaces on different levels of the station are organized, not as separate episodes, but linked in a continuum created by the perceptual experience of travelers passing through the various environments.

The atrium level, below street level, is the one that most reflects the proximity to the surrounding monumental landscape, sharing the ancient level with the adjacent Temple of Peace. The large space, unusual for other stations, unintentionally evokes a basilical environment, which was emphasized in the project by giving strength and prominence to the two ends, facing respectively towards the Imperial Fora and the Colosseum, where two exhibition areas are located. In the center of this space, there is the large stairwell, another exceptional element for a Roman station, offering an important opportunity due to its size and depth.

For this reason, this space also takes on the role of a luminous gem, characterizing its narrative dimension through the choice of finishing material that interprets it as a precious and participatory place within that architectural scale and geometric dimension alluding to the rigor and measure of a forum; a kind of Forum within the station.

The 5 Areas

• In Area 1, various installation devices, both physical and digital, including audio systems, are concentrated. The exhibition system of the narrative boxes consists of devices containing video projections. The exhibition system of hidden reconstructions consists of reconstructions with three-dimensional videos hosted above the ceiling, which can be discovered from below through periscope viewers. The exhibition system of the narrative ceilings consists of multimedia rooms with monitors, video walls, and projections, visible above the ceiling. The exhibition system of the film rooms consists of spaces defined by dark and reflective surfaces – walls, floor, and ceiling – perpendicular to each other, in which projections and video walls are reflected and multiplied throughout the room.
• Area 2 is the space dedicated to the functional wells in which the fundamental role they played in the daily life of the city in archaic times is highlighted through an exhibition that stages their dense presence in the area. It does so by showing, as in a kind of large section of the ground, the interior of six wells that thus reveal the technical knowledge and the high quality of their construction. This area is located in the eastern part of the atrium, near the connection to metro B, and consists of a sort of exhibition room, lower by fifteen cm compared to the floor level, protected by a glass railing that will allow the observation, at the right distance but without filters, of the archaeological finds in their natural state. The space where the wells will be installed, just after the large lowered beam that marks the eastern limit of the atrium, will be more than four meters high and, through circular mirrored surfaces placed inside the reconstructed structures, will try to restore their verticality, producing an effect of openness both upwards and downwards. The six wells will be connected with oxidized sheet panels to convey the idea of mass and materiality that characterized the original spatial context of discovery.
• In Area 3, the wall structures related to a building, probably residential, from the late Republican period found below the Velia, near the Colosseum, are re-proposed in situ. In close visual relationship with these finds, the back wall of the mezzanine has been divided into several display cases: the first two on the left side of the wall will house some opus sectile floor fragments and mosaics. The largest display case, slightly inclined to match the same position of the wall structures in front, contains the singular find of the reed room.
• Area 4 is the second exhibition area on the Correspondence Floor and occupies the eastern sector of this vast space. The museographic theme focuses again on wells, similar to Area 2 above, but with the intention of telling their second life, i.e., their functioning as “ritual deposits,” probably related to offerings linked to the sanctity of water. Here the exhibition proceeds, always starting from the dense presence of the wells, which are again sectioned, but this time horizontally, thus making the interiors with their ritual contexts visible in their original configurations. Three are the sectioned wells, while a fourth well, about 3.8 meters high, is completely reconstructed to visually convey the concept of the well as a protective shrine for the ritual dimension of worship. The three sectioned wells produce horizontal display cases arranged in a system by a single horizontal plane that serves as a narrative surface and support for the understanding of the exhibited materials.
• Finally, Area 5 is the area where the narration takes on a role less directly linked to archaeological data but no less important for it. It is the space where the aesthetic dimension of the forums and their architecture, defined mainly by the concept of a perimeter enclosure, is evoked. Area 5 is the area of the station’s forum, the place where the aesthetic and monumental character of the space is entrusted to the vertical dimensions