Rome has its own "hop-on, hop-off" sightseeing buses. The Trambus Open Roma 110 bus leaves with 10-minute frequencies from Piazza dei Cinquecento (at the main Termini station), with a two-hour loop including the Colosseum, Piazza Navona, St. Peter's, and the Trevi Fountain. Tickets are €18, depending on whether you want to hop on and off or just stay on the whole time. There is also a Tram Open Bus by Night, only on Friday and Saturday and it leaves from Piazza Venezia at 10 pm and 10:30 pm (€12). A variant is the Archeobus (€12), which departs every 20 minutes from the Piazza dei Cinquecento and heads out to the Via Appia Antica, the Colosseum, and the Catacombs. Tickets can also be purchased ahead of time online (www.trambusopen.com).