By Car -- To reach Río Dulce by car, take the Carretera al Atlántico (CA-9) out of Guatemala City to La Ruidosa crossroads at Km 245. From here it's another 34km (21 miles) north on highway CA-13 to Río Dulce. Highway CA-13 also connects Río Dulce with Flores, Tikal, and El Petén.
By Bus -- Litegua (tel. 502/7930-5251 in Río Dulce, 2220-8840 in Guatemala City; www.litegua.com), Autobuses del Norte (ADN; tel. 502/2251-0050; www.adnautobusesdelnorte.com), and Línea Dorada (tel. 502/2232-5506; www.tikalmayanworld.com) all have direct daily service between Guatemala City and Fronteras, Río Dulce. All have terminals within a couple of blocks of each other in Zona 1. Between the three lines, buses begin leaving around 5am and leave at least once every hour, with the last departure around 2pm. The trip from Guatemala City takes about 5 1/2 hours, and fares run between Q60 and Q188 ($8-$25/£4-£13) one-way. Splurge for one of the "executive" or "deluxe" buses, which are more modern, comfortable, and faster. Alternatively, you can take any bus to Puerto Barrios, get off in La Ruidosa, and wait for a local bus to pass on its way to Río Dulce. Or, if you're coming from Antigua or Panajachel, all of the local tour agencies can arrange a scheduled minivan transfer to Río Dulce for Q263 to Q300 ($35-$40/£18-£20).
There's also regular bus service between Río Dulce and Flores, Petén. Línea Dorada and ADN both run this route, which takes about 3 1/2 hours each way.
By Boat -- Río Dulce is serviced by regular boat-taxi service from both Livingston and Puerto Barrios. The main boat dock is located at the base of the bridge on the Fronteras side. Collective boats leave Río Dulce for Livingston from the main dock at 9 and 11am and 1pm every day. The fare is Q115 ($15/£7.50) one-way; Q180 ($24/£12) round-trip. Other boats will run throughout the day once they fill to capacity, or you can rent a boat that will hold up to 10 people for around Q750 ($100/£50).
For many purposes, boats are the preferred means of travel. Head to the main boat dock in Río Dulce, where you can catch regular service to Livingston and El Castillo San Felipe. You can also hire a small motor launch to take you around for Q375 to Q750 ($50-$100/£25-£50) for a half-day.
For land travel, taxis are readily available on the main road through Fronteras. If you can't flag one down, have your hotel call one for you.
There are hotels and restaurants clustered around the shores of Río Dulce, on both sides of the bridge, and farther afield. While the whole area is most commonly referred to as Río Dulce, there are more specific designations here. Approaching from Puerto Barrios or Guatemala City, the area around the base of the bridge is known as El Relleno. After crossing the bridge, you'll come to Fronteras, the larger and more important settlement.
Fast Facts -- Banco de Comercio (tel. 502/7930-5141), Banco Industrial (tel. 502/5514-0888), and Banrural (tel. 502/7930-5159) can all be found on the main road in the center of Fronteras. The Centro de Salud health center (tel. 502/7390-5209) is also in this area. The number for the local police is tel. 502/5306-5873.