When speaking of the beautiful islands of Hạ Long Bay, one must speak of Bồ Hòn Island or Soap-Berry Tree Island, not only because of its splendid scenery, but also as it is one of the largest in the area. There are many grottoes located here, such as the Surprise, Luồn, Virgin and Male grottoes. There is also a concentration of high mountains with vertical cliffs like citadel wall; mountains follow closely make a huge beautiful watercolour picture on the sea.

There are various species of plants such as benjamin fig trees, cycads and orchids... and animals are monkeys, deer and chamois. Perhaps, Bồ Hòn Island famous for the grotto system hiding inside it. Each of them has their own marvellous beauty and is related to the moved legends.