Ban Than reef is about 35 km from Tam Ky city and 80 km from Hoi An city. Along the coast line of Quang Nam with blue water and white sand, there suddenly emergs a black rock cliff heaping up like coal, it is 02 km in length and 40 metres high, combined with a stone edge to make a unique natural sculpture. From the top of Ban Than, tourists can look out over the vast area of sea, with Hon Ong - Cham islands  in the long distance.