Portobelo National Park, a World Heritage site, isn't far from Colon. Fabulous for divers and snorkelers (especially during the off-season, when the balmy water isn't as full of tourists), the park is equally suited for old-fashioned hiking, too. Bring binoculars to enjoy the world-class bird-watching. If you're a history buff, you can stand where Christopher Columbus once stood.
The rainforest around Gatun Locks is closer to Panama City than Colon, but there are plenty of operations that can take you there from the other city. If you're an adventurous traveler, it's a destination you'll likely treasure. Various operators in the forest offer all sorts of ways to get to know the rainforest, including zip lines, rope bridges strung high in the canopy, intense jungle hiking, and catamaran tours around Gatun Lake. It's a hub for ecotourism, too, so you'll get quite an education on sustainability while you're swinging Tarzan-like through the trees.
Situated high on an ocean-side bluff over the mouth of the Chagres River, the view from Fort San Lorenzo is stunning. Because of the 270-degree view of the ocean and river, the fort has seen many bloody battles between explorers and natives. It was originally built in the 16th century to guard a Spanish treasure route, and now it's the fort that's the treasure. The stone ruins are home to scores of rare birds, mammals, insects and plants.
Adventures Panama operates a white-knuckle whitewater rafting tour of the mighty Chagres (in class II and III rapids) from June to February. The water is clear and the flora and fauna sightings are plentiful, including river otters and plenty of monkeys. Expect to spend five hours on the water and a couple of hours hiking to and from the rafts. You can even opt for overnight accommodations, and maybe even share a drink with a local campesino as you watch the sun go down over the river.
