was a town located in Mihara District, Hyōgo Prefecture, Japan. It consisted of a part of Awaji Island and the much smaller . It is located at the southern end of Awaji island, from which it also derived its name.
As of 2003, the town had an estimated population of 18,921 and a density of 217.63 persons per km<sup>2</sup>. The total area was 86.94 km<sup>2</sup>.
On January 11, 2005, Nandan, along with the towns of Mihara, Midori and Seidan (all from Mihara District), was merged to create the city of Minamiawaji.