San Lorenzo in Nicolanaso was a deconsecrated church, now demolished, that used to be under the Capitoline Hill in Via della Consolazione. This is in the rione Campitelli.
The first documentary mention of this little church is in 1192, although it was older than that. It was also known as San Lorenzo sub Capitolio and San Lorenzo de Palpitariis. No explanation of the very odd name Nicolanaso seems to be on offer.
It drops out of the documentary evidence in the mid 16th century, and seems to have been deconsecrated and turned into a private house then. As such, it survived for four hundred years until the systematic demolition of most of the mediaeval buildings on the west side of the Capitoline by the Fascists. It was demolished in 1943 -a tragedy, as only a little longer would probably have meant that it would still be with us.
Before everything to the north of the present Vico Jugario, Piazza di Santa Maria della Consolazione and Via della Consolazione was demolished, the last-named street had a very tight squeeze round the far left hand corner of the nave of Santa Maria della Consolazione. This corner, which has a Corinthian pilaster, lined up with the left hand corner of this former church's façade on the other side of the street. The line of the frontage is marked by the roadside line marking off the parking bays there now.
Despite being so long deconsecrated, it looked like a church. Two gateways, the left hand one square and the right hand one arched, had been punched through the façade on either side of the former entrance. The latter had been reduced to a small door slightly to the right of centre, but a fragment of an ancient column was still included in the fabric on the left hand side, at the right hand corner of the gateway there, and this seems to have been part of the original entrance. The right hand arched gateway had walling added around it, presumably to strengthen the fabric.
Above the entrances were two rectangular windows, of different sizes. In between these was a fresco of the Crucifixion, showing Christ on the cross accompanied by Our Lady and St John the Evangelist. This was round-headed, and protected by a gabled canopy. There was nothing in the gable of the building.
Intarch web-page (Beware, name is given wrongly.)