A visit to the Con Dao Archipelago will mostly be spent on the only inhabited island - Con Son. It's one of those magical places blessed with spectacular beauty, a delightful colonial era old town, a serene atmosphere - masking a cruel historical backdrop.
You can easily spend a couple of days exploring Con Son. The prison ruins and the museum will keep you busy for half a day or more. And the thought of the tens of thousands who perished here at the hands of the French and then US backed South Vietnamese regimes will remain with you long beyond your stay.
Con Son Island is compact and cycle friendly - though there are some challenging hills if you're planning on exploring the entire island by bike. Motorbikes are also available for hire. Traffic is light.
The surrounding islands are largely uninhabited, except by a rich array of wildlife and their protectors, but can be visited on boat trips from Con Son. This is one of the most unspoiled and fragile coastal eco-systems in Vietnam. Its population of sea turtles has been nurtured in a programme run by the World Wildlife Fund.