Tam Hai lies off the southern coast of Danang and covers more than 15 square kilometres, over half of which is water. Surrounded by the sea on three sides, the island remains accessible only by ferry.
From above, Tam Hai resembles a giant whale stretching from the sea towards the mainland. Its “tail” is the Ban Than rocky outcrop, where geological formations are estimated to date back about 400 million years.
The Ban Than-Hon Mang-Hon Dua landscape complex, one of the island’s main attractions, was recognised as a national site in 2023.
Ban Than is a rocky headland jutting into the sea, while Hon Mang and Hon Dua are small islands a few hundred metres offshore. The area is particularly known for layers of glossy black rock stacked naturally along the coast.
According to local records, the formations bear traces of geological processes dating back hundreds of millions of years and are considered a rare geological feature in Vietnam.
Tam Hai is also home to a cemetery in Thuan An Village containing more than 500 graves for whales that have washed ashore over generations.
Local fishing communities traditionally regard whales as protectors at sea. When one washes ashore, villagers hold a funeral and burial ceremony, a custom passed down through generations.
The cemetery is also associated with the annual Cau Ngu, or whale-worshipping festival, a traditional event closely linked to the lives and livelihoods of local fishermen.
Tam Hai is also known for its coconut-lined roads and two ancient freshwater wells at the foot of Ban Than Mountain.
About 500 metres apart and roughly one kilometre from the coast, the wells are around two metres wide and 10 metres deep, with walls built from carefully arranged laterite blocks.
Their exact age and origins remain unknown. Local residents say the wells have existed for generations and have never completely dried up, even during prolonged droughts.
Fishing and aquaculture remain major livelihoods on the island, while tourism and services are being developed around Tam Hai’s marine landscapes, local culture and community-based experiences.