San Lorenzo ai Monti was an ancient parish church that stood in what is now the roadway of the Via dei Fori Imperiali, at its junction with Via San Pietro in Carcere.
The dedication was to St Lawrence of Rome.
The first documentary reference dates from the mid 10th century, when it was noted by the future Pope Leo VIII (963-5) in his capacity as protoscrinarius to the Holy See. In 1199 it was made a dependency of Santi Sergio e Bacco al Foro Romano, but was later parochial.
In the Middle Ages it was known as Sanctus Laurentius de Ascesa Proti, but by the 15th century was known as San Lorenzolo owing to its being a very small church. It kept this nickname until its end.
In 1704 the church was given to the religious congregation of the Pii Operarii Catechisti Rurali, but they did not stay there long since they moved in 1732 to San Giuseppe alla Lungàra where they remain.
The façade was restored in 1840, and the interior in 1860. After then, the church was used by a community of expatriate Russian Catholic converts and so the Byzantine rite liturgy was celebrated here. This arrangement continued until the opening of the Russian College and its church of Sant'Antonio Abate all'Esquilino.
The little church was demolished in 1931 by the Fascists to clear the route for the Via dei Fori Imperiali.
Originally, the church stood on the east side of a piazza on the Via di Pie del Mercato, which ran north to south just east of the present Vittorio Emanuele monument. Another lost street called the Via del Marforio ran eastwards of this piazza in the direction of the Salita del Grillo, but its north frontage had already been demolished by the mid 19th century. The entrance of the church was on the south side of the street, and the orientation was north to south.
The site is on the north-west side of the Via dei Fori Imperiali, at the west end of the raised walkway running across the excavated remains of the Forum of Trajan. The church was on the north-west corner of the triangular paved area at the start of this.
This was a very small church, and the plan was a simple rectangle. The façade was also simple, yet effective. The triangular pedimented doorway had the same proportions as the triangular pedimented façade as a whole. The only detail was a rectangular window above the doorway.
There was a small Romanesque campanile to the left of the far end.
The interior was divided by a pair of wide ribbed Doric pilasters with sweeping sides, that supported the vault springers without an entablature. On the far side of these were two side altars, inserted into arched niches with molded archivolts and Doric pilasters. Each of these was in turn enclosed in an aedicule formed of two Corinthian pilasters on plinths, supporting an entablature with a projecting cornice, above which was scrollwork decoration in stucco.
The shallow presbyterium was marked off by a triumphal arch, slightly horizontally elliptical, with the molded archivolt fitted in just under the vaulting and supported by Doric pilasters. The archway leading into the tiny rectangular apse was treated in the same way, and the decoration of the capitals of the triumphal arch pilasters were continued as a string course on the walls of the presbyterium to pass across the apse arch pilasters and down the side walls of the apse itself.
The main altar was against the back wall of the apse, with a coloured marble frame for the altarpiece above. This showed St Lawrence and was by Giovanni Alberti.