The proposal for the northbound extension of the B1 Subway Line arises from the problem of heavy traffic congestion in the north quadrant of Rome. The B1 subway line is a new branch of the B line, consisting of 4 stations and a track of about 4 km.Libia is characterized by a lowered square leading to the entrance hall of the station. All levels are visible from the hall through a particular irregular light-well that crosses the whole section of the project. The monumental light-well guarantees day-lighting up to the lower level of 35 meters underground and emerges on the square through a big volume made of aligned glass shafts. Annibaliano has its entrance on a sinuous underground square with a concrete inner façade articulated in a sequence of luminous recessed forms and volumes. The square figures as a wide open space which provides the city with a new central space while being the architectural urban core of the new station. The station is accessible from three principal entries: Via Asmara, Via Bressanone and Corso Trieste. Mechanical systems and fixed staircases ensure the connection between street and rail tracks; the intermediate level opens the accesses to the lower level of the station, which is provided with rail functions and services. Annibaliano square comprises a public green space and pedestrian areas.Compared to the preceding project of the company Tecnimont Engineering, ABDR has radically changed the wide area of Conca d’Oro between Ponte delle Valli and Viale Tirreno, creating a large subterranean space, lit from above and surrounded by commercial buildings (2.000 m2) – the first and only national example – while enriching qualities and uses of such large spaces. Conca d’Oro develops in 18.000 m2 of a very complex internal and external layout. The external areas of the station consists of a 10.000 m2 green park overlooking the roof of the three-storey exchange parking complex.