As it charged towards the coast, its flailing tail gouged out valleys and crevasses. When it finally plunged into the sea, the area filled with water, leaving only the pinnacles visible.
Designated a World Heritage site in 1994, this mystical landscape of limestone islets is often compared to Guilin in China or Krabi in southern Thailand. In reality, Halong Bay is more spectacular. The bay’s immense number of islands are dotted with wind- and wave-eroded grottoes, and their sparsely forested slopes ring with birdsong.
Read more: http://www.lonelyplanet.com/vietnam/northeast-vietnam/halong-bay#ixzz3q500XQrv