Santa Caterina dell' Esedra was a 16th century devotional chapel situated just where the Via Nazionale now joins the Piazza della Repubblica. This is in the modern rione Castro Pretorio.
The dedication was to St Catherine of Alexandria.
The maintenance of this edifice before 1870 was a devotional exercise on the part of the Cistercian monastery of San Bernardo alle Terme, and honoured the patron saint of their founder. She had been Caterina Sforza Cesarini, niece of Pope Julius III, who had arranged the conversion of a corner rotunda of the Baths of Diocletian into the new monastery church of San Bernardo in 1598. As well as paying for this and for the new monastery complex, she had the little chapel built as a memorial to herself.
The chapel was demolished when the Via Nazionale was built. This was one of the last proposals of the Papal government before the conquest of Rome by Italy in 1870, in order to give a proper route from the railway station to the city, and the instigation of the work was one of the first acts of the new government in 1871.
The Nolli map of 1748 shows this little building as having a transverse rectangular plan, with an apse.
Back then, the exedra of the baths was occupied by the garden of the abbey, the buildings of which where to the south of its church. A massive wall on ancient foundations followed the curve of the exedra, and a screen wall took a tangent to enclose the garden. There was a small gate in the latter from what was then the Piazza di Termine (now part of Piazza della Repubblica), and a path ran from this to the far point of the exedra wall. The chapel entrance was here; the whole layout was hence symmetrical with the chapel as the focus of the garden. The body of the chapel was on the other side of the exedra wall, in what was then the monks' vineyard.
The site is exactly under the roadway of the Via Nazionale, and the curve of the present buildings on the Piazza della Repubblica, when extended across the road, gives the line of the façade.