The area occupied by the ex Post Office building on the main square of Terni, piazza della Repubblica, was once the location of the church of San Giovanni Decollato. A baroque church, with a large dome and a facade rich in friezes, capitals and columns. It was demolished in 1921 and its vestiges transported to the Passeggiata public gardens where they were reused as bases for brick benches, corner columns and park embellishments.
The Post Office building was built in its place, completed in 1936,
in compliance with the activity of the public office that wished to be present on the main square of all Italian cities.
Within the general framework of the realisation of a city with a modern look, the task of planning the Post Office building was entrusted to Cesare Bazzani who had already completed many interventions in Terni. The monumental arches at street level were designed by Bazzani, the classical forms. The building was only partially built. The main facade does not appear to be that which looks out onto the square but the one on the side which opens onto via del Plebiscito. On the back, on the present day piazza San Giovanni Decollato, a brief staircase recalls an apse and is very similar to the basement of a Roman building which recently came to light and still visible in the underground car park built on the site.
The building of Palazzo delle Poste was part of restructuring plan for the entire right side of the city's main square, in accordance with the urban planning of 1919. Together with the post office building, a sort of urban gallery was supposed to have been built but this part of the project has never been actuated.
The piazza della Republica facade of the post office building is, however, in some way, almost preparatory to the hypothetised gallery, thanks to the large porch whose columns support the two upper levels, planned with wide windows to lighten the appearance. The building was then extended with the posterior apse as well as a cant.
The other side of the building, that looking onto via del Plebiscito, presents somewhat different traits, not possessing the "gaps" of the piazza della Republica side, but the"movement" is ensured by a slight advancement of the central part, as well as a casual use of decorations and sculptures.
The interior of Palazzo delle Poste presents the monumentualistic and classical traits typical of the works of Cesare Bazzani.