The islands are composed of magmatic rocks of different ages. Hon Bay Canh, Hon Cau, Hon Bong Lang composed of Cretaceous microgranit rocks. The Northern part of Con Dao Island composed of quartz diorite and granite - granodiorit of late Mesozoic- early Cenozoic age, and is partially covered by Quaternary marine sediments. The Southern part of this island and Hon Ba island are composed of the riolit and intrusive formations of unknown age. On the western slope of Con Dao Island, there exist of outcrops of diorite and microgranit penetrated by big quartz bands.
Formally a Khmer Empire territory known as Koh Tralach, the islands were settled by the Vietnamese by the 17th century. On June 16, 1702, the English East India Company founded a settlement on Pulo Condore as an entrepôt for ships plying between India and China. Three years later, on 2 March 1705, the Vietnamese murdered the English agents, destroyed the factory, and expelled the remaining settlers. During the internecine wars for the Court of Hue, the Nguyen Prince Nguyễn Phúc Ánh ceded the islands to France in the Treaty of Versailles (1787) in return for military assistance. The treaty however was abrogated as France failed to provide the aid.
Con Dao Islands, also known as Con Dao National park, are an archipelago of 16 mostly uninhabited islets just off the southern coast of Vietnam, each of which offering expansive beaches shaded with evergreen trees. Great for savvy travellers looking to escape bustling city life, the main island also boasts miles of coastal roads, hiking trails and a wide range of outdoor activities.
Aside from this rather bleak part of Con Son, the island has plenty of unspoilt beaches where you can enjoy a day of sunbathing, swimming, and dining on fresh seafood. Closest to the town is Bai An Hai Beach, which connects Ben Dam Harbour to several beachfront resorts and fishing villages. If you prefer privacy, rent a motorbike and make your way south towards Mui Ca Map (Shark Cape) and Nhat Beach to enjoy fine white sands and breathtaking views of the ocean.
Island-hopping and diving are popular activities on Con Dao Islands, where you can explore most of the uninhabited islets and spot various wildlife such as stingrays, barracudas, moray eels, and dugongs. Due to its status as a national park, you need to arrange your trip with Con Dao National Park Headquarters (29 Vo Thi Sau, Con Dao District, Ba Ria - Vung Tau Province). Hon Bay Canh Island is renowned for its turtle breeding grounds, so if you’re visiting between June and September, you may even get a chance to watch turtles laying their eggs.
On Con Dao, the fun can start with a sightseeing trip on the back of a motorbike. It is the best a way to see the real island. There are beaches to swim or sunbathe or you can go trekking in the tropical jungle. Offshore is also known as one of the best places to dive in Vietnam too.
Con Dao is beautiful and very quiet at night. Nightlife activity here is still very limited. It can be quite simple – eating out at one of the local restaurants, followed by drinking Vietnamese coffee or tea or beer probably at the same venue.