Ghenh Da Dia

Ghenh Da Dia is a famous coastal geological formation in An Ninh Dong, Tuy An District, Dak Lak Province (formerly Phu Yen Province), about 35 km north of Tuy Hoa city. It is notable for thousands of interlocking hexagonal and polygonal basalt columns formed by volcanic activity millions of years ago. Recognized as a National Natural Heritage site in 1998, it is one of Vietnam's most distinctive natural landmarks and a major sightseeing attraction along the central coast.

Visitors can expect a coastal headland covered with dense, tightly packed basalt columns forming flat, disc-like steps extending to the sea. The columns are mostly hexagonal, dark grey to black, creating a natural paved surface and small pools with seawater. The site overlooks the East Sea with views of waves breaking against the rocks, a small lighthouse area, and an open coastal landscape. Visitors explore on foot along designated paths and over the rock surface, with areas for photography and viewing the sea.

Formed by volcanic activity during the Miocene period with basalt lava flows cooling and fracturing into polygonal columns. The site was designated a National Natural Heritage by the Ministry of Culture, Sports and Tourism in 1998 due to its geological value.

Considered a symbol of the coastal landscape of former Phu Yen Province, now Dak Lak Province, and associated with local folklore about the stacked stone discs. It is a prominent cultural and natural icon featured in provincial tourism promotion.