Privately owned air-conditioned buses are the cheapest way to get around the country and connect Puerto Plata with Santo Domingo. The one-way fare is about $7.50, and the trip takes 3½ hours. Just be aware that buses can be packed, especially on weekends and holidays.
Caribe Tours (809/221-4422). Linea Gladys (809/565-1223 in Santo Domingo; 809/539-2134 in Puerto Plata). Metro Buses (809/566-7126 in Santo Domingo; 809/586-6062 in Puerto Plata; 809/587-4711 in Santiago).