There are buses from Helsinki's Central Bus Station to Porvoo every 15-30 minutes. Standard/express services cost €10.30/13.20 one-way and take 55/65 minutes, so the surcharge is hardly worth it — the expresses just stop in Porvoo on their way to points further east.
There is no regular passenger train service to Porvoo, but the Porvoo Museum Railways run a vintage 1955 Lättähattu ("Flat Hat") Dm7 from Kerava to Porvoo and back on Saturdays in July/August only. The trip takes 1.5 hours and costs €15/25 one-way return for adults, half price for children, no reservations, and cash only. As of 2009, the train leaves Kerava at 12:10 and sets off back from Porvoo at 4:00 PM. Kerava, in turn, can be reached in 20 min by regular commuter train from Helsinki's Central Railway Station.
M/s Runeberg cruises from Helsinki to Porvoo between May and September three to five times a week, departing at 10 AM and returning at 4 PM. The trip takes 3.5 hours one way and costs €25.00/36.00 one-way/return, half price for children. On Saturday, you can also opt to take the boat one way and the train back. The boat leaves from Linnalaituri on Helsinki's Market Square, opposite the President's palace.
Porvoo is easily accessed via the E18 expressway east from Helsinki towards Kotka and the Russian border. The other option is the old Porvoo road, Highway 170, but it's considerably slower and not particularly scenic.
Bike fans may want to consider pedalling the 78 km along the scenic King's Road from Helsinki to Porvoo, or 50 km along the more direct Highway 170.
Porvoo is best explored on foot: the pedestrian zed Old Town is compact and all main attractions can be easily reached from the bus, ferry or train stations. Parents will, however, probably want to leave the baby carriage at home: the Old Town's streets are cobblestone and often hilly.
There used to be horse and carriage
