Introducing Con Dao National Park
From March to November it’s possible to do a beautiful and leisurely two-hour trek starting from near the airport runway, but you’ll definitely need a local guide to do this (about US$6 for the outing). The walk leads through thick forest and mangroves, and past a hilltop stream to Bamboo Lagoon (Dam Tre). This spot is stunning and there’s good snorkelling in the bay. You could even consider arranging for a boat to come and pick you up.
A hike that you can do yourself is a 1km walk (about 25 minutes each way) through rain forest to Ong Dung Bay. The trail begins a few kilometres north of town. On the road to the trailhead, you’ll also pass the ruins of the Ma Thien Lanh Bridge, built by prisoners under the French occupation. The bay itself has only a rocky beach, though there’s interesting coral 300m off shore.
Rainbow Divers (630 023; firstname.lastname@example.org) runs an office out of the Phi Yen Hotel, though they’re scheduled to move to ATC sometime in 2007. They offer some excellent dives among the coral reefs around the islands. During the dry season (November to May) visibility is good and dives are less likely to be cancelled. This is also a good source of island info (English spoken).