Rimini
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.
Roman ruins -
Town Museum (Museo della Citta) - For an introduction to ancient Ariminum, start with this museum.
Rooms have been re-created (dining room and surgeon's office), so kids can get a sense of ancient Roman daily life. In the dining room, kids can put on costumes and pretend to have their own ancient meal.
Also, see stellar mosaics of Roman ships, Medusa, fish, mythical animals, and also medical tools from the Surgeon's House next door.
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.
Go to the beach - Rimini is a seaside resort, with miles of long sandy beaches, equipped with umbrellas, beach chairs. In most sections of the beach, renting beach chairs is required. Free beach areas are very crowded in July and August.
Italy in Miniature (Viserba, north of Rimini) - Italia in Miniatura is a theme park where you can see the historical monuments of Italy in miniature. It's the best way to get an overview of the country, literally. Check out the pint size versions of Piazza San Marco in Venice and the Grand Canal, monuments of Florence or St. Peter's in Rome, or have fun on the go-karts, monorail and Pinocchio fairytale ride.
Acquafan (Riccione, south of Rimini) - On a hot day, when you've had enough high culture, relax in the Acquafan water park. Children's pools, a big wave pool, shows, cafes, grassy areas, kids play areas.