The Capitoline Apartment Block

Often overlooked by tourists scurrying to or from the steps up to Capitoline - sandwiched between these and the steps of the Victor Emmanuel monument - is a well preserved Roman apartment block (or insula). A rare survivor in Rome itself, this five storey block was buried beneath the 17th Century church of S. Rita, which was built on the remains of an earlier church - S. Biagio "of the Market" which dated from the 12th / 13th Centuries. S. Rita's was demolished in 1927, and the apartment block uncovered.

It is a fresco from the earlier church that you can see roughly at today's street level, though the church was actually built into the 3rd and 4th floors of the insula. The later church got its name from its proximity to Trajan's Market, and this insula was built around the same time they were, in the 2nd Century CE.
The lower portion, which you can now see deep below you, was buried by the rising ground level.
These lower storeys would have contained shops. The fourth floor - due to the hill behind sloping back - was big enough for 11 rooms. These cramped, lightless chambers would have housed some of the very poorest of Romans, perhaps even slaves employed on the Capitoline or on the Palatine, though the latter had extensive slave quarters of its own.