Casco Viejo — Panama City's colonial old town, a UNESCO World Heritage Site, is 8 kilometres away and worth a half-day. The colonial Spanish streets, restored churches, and seafront promenade are among the best urban heritage in Central America. The contrast with Balboa's American-colonial atmosphere is striking.
Gamboa — Follow the Canal north through the rainforest to Gamboa, about 35 kilometres from Balboa. The Gamboa Rainforest Resort has a nature centre and boat trips on the Canal, and the Pipeline Road nearby is one of the world's top birdwatching sites — hundreds of species have been recorded there. A taxi or rental car is the practical way to get there.
Barro Colorado Island — Book a guided tour through the Smithsonian Tropical Research Institute. The boat departs from Gamboa; the tour includes a guided walk in old-growth rainforest with howler monkeys, coatis, and hundreds of bird species. Half-day or full-day options available; reserve well in advance.
Portobelo — On the Caribbean coast, about 100 kilometres north of Panama City. A ruined Spanish colonial fortress town and UNESCO World Heritage Site where the conquistadors loaded silver from Peru onto the treasure fleets. The drive through the mountains is scenic. Half-day by car; combine with a stop at the Gatún Locks on the Caribbean side of the Canal if you want a second locks experience.
San Blas Islands — The Guna Yala archipelago on the Caribbean coast, accessible by small plane from Albrook Airport (30 minutes) or by a combination of car and boat (4–5 hours each way). White sand, turquoise water, and indigenous Guna culture — a different world from Panama City. Better as an overnight or two-night trip than a pure day trip.