The construction of the Arch of Riccardo probably dates back to the middle of the 1st century BC. and it has a height of 7.20 meters, width of 5.30 meters, depth of 2 meters and a plant motif in the archway.

The Arch is located on an ancient Roman road and it is assumed that it was a gate of the city walls of Tergeste, the Roman Trieste founded by Octavian Augustus, or the entrance to a sacred area dedicated to the Magna Mater. Even during the Middle Ages, the Arco di Riccardo retains the function of a door within a wider defense wall system.

There are several legends about the origin of the name. According to some, the choice was made in honor of King Richard the Lionheart held prisoner in Trieste on his return from the Holy Land. According to others, it derives from the deformation of the name King Charlemagne at the time of Frankish domination in Trieste between 787 and 788 or from the dialectal deformation of the Latin word “cardo maximus”, the name of one of the two main streets of Roman cities (the another is the “decumano maximus”).