(now known as Trevi nel Lazio)
Trevi was a 2nd class distribution office, reporting to Frosinone. In 1871, Trevi had a population of 1,899.
Trevi, May 13, indistinct year in the 1850s, 1 bajocco black on blue green 1852 pays the rate for a single letter within the same direzione postale. Frosinone May 16 transit marking on front.