
Rimini was founded as a Roman colony (Ariminum) in 268 BC, and ancient ruins are preserved to this day. In 49 BC, Julius Caesar crossed the river Rubicon into Rimini, addressed his troops ("the die is cast") and began his war to become dictator of Rome. In the Piazza Tre Martiri (once the Roman forum) is a statue of Julius Caesar.
Town Museum (Museo della Citta) - For an introduction to ancient Ariminum, start with this museum.
Surgeon's House (Domus del Chirurgo) - Go next door to the Surgeon's House, where the ruins preserve exquisite mosaics on the floors. Built in the 2nd century AD, the two story house had two living rooms, bedroom, dining room, kitchen (on the second floor), latrine. Particularly beautiful is a mosaic of Orpheus, surrounded by animals. After house was abandoned, it was used as a cemetery, and you'll see buried skeletons in the mosaic floor.
Augustus Arch - The ancient Roman road, Via Flamina, went from Rome to Rimini. The end of the Via Flamina was marked with the Augustus Arch. In the Middle Ages, crenelations were added to the top of the arch.
Roman amphitheater - Kids can run around the ruins of the amphitheater, which was almost as big as the Colosseum, and could hold ten thousand spectators.