San Marino sits on Monte Titano, a ridge rising above the Italian region of Emilia-Romagna, and the whole republic can be seen in a day. Three towers along the crest, a walled historic center and long views toward the Adriatic are what most visitors come for; Rimini on the coast is under an hour away.
The guides on this page cover San Marino as a whole. The old town is steep and largely stepped, which shapes how long things take on foot. There are no border formalities arriving from Italy, and the euro is used. Day-trip traffic concentrates in the middle of the day during summer, so early or late visits give a considerably quieter version of the same place.