Witness one of Vietnam's most extraordinary natural masterpieces at Ganh Da Dia (often translated as The Cliff of Stone Plates or Da Dia Reef), Phu Yen province's most iconic attraction. This unique geological formation is a stunning seaside spectacle composed of thousands of interlocking basalt columns, formed by volcanic eruptions millions of years ago and cooled into remarkably uniform polygonal shapes. Stretching along the coast like a giant, natural honeycomb or a colossal stack of plates, it's a sight that truly has to be seen to be believed and is recognized as part of the Phu Yen UNESCO Global Geopark.  

Visiting Ganh Da Dia allows you to walk directly (with care) onto these fascinating rock formations, examining the intricate patterns of hexagonal, pentagonal, and circular columns up close. Feel the texture of the ancient volcanic rock and watch as the blue waters of the East Sea crash against the dark stone edges, creating a dramatic contrast. The nearby Ganh Den lighthouse offers another perspective overlooking the reef and surrounding coastline, enhancing the experience. This unique landscape provides incredible opportunities for photography.  

Ganh Da Dia is an absolute must-visit when exploring Phu Yen, offering a natural wonder unlike almost anywhere else on Earth. It's typically accessed as part of a day trip north from Tuy Hoa city, often combined with visits to O Loan Lagoon or Mang Lang Church. Be prepared for potential crowds, especially during peak times, and wear sturdy shoes for walking on the uneven rock surfaces. This geological marvel is the defining landmark showcasing Phu Yen's unique and dramatic coastal beauty.