Portobelo sits between a provincial port city to the west and a stretch of undeveloped Caribbean coast to the east, with Panama City reachable in a long half-day. All three directions reward a day away from town.
Colón is the closest city, about 45 minutes west by bus or car. It is a rough-edged port town with a complicated reputation, but the free-trade zone on its edge is the largest in the western hemisphere and it has a certain gritty energy. The Zona Libre aside, most visitors come through on their way to the Panama Canal's Atlantic locks at Gatún, which are worth seeing. Stick to the main streets and travel in a group.
Nombre de Dios, further east along the coast road, was the original Spanish treasure port before Portobelo superseded it in the 1590s. It is quieter and less visited, with a small beach and the remnants of an even older colonial past. The road there is rough in places but passable in an ordinary car in dry season. A local boat can also make the journey along the coast.
Isla Grande is not in the location hierarchy but deserves mention: a small island a short boat ride east of Portobelo, popular with Panamanian weekenders for its calm Caribbean water, simple seafood restaurants, and unhurried pace. Boats leave from La Guaira, just east of town.
Panama City is roughly 2.5 hours west by car along the Caribbean highway and then the Transístmica. The journey is easy and the capital repays a full day — the Casco Viejo neighbourhood, the Canal visitor centre at Miraflores, and the Biomuseo (designed by Frank Gehry) are all within reach. Bus connections run regularly from Portobelo via Colón.