[4] Its highest point is Kai Kung Leng (雞公嶺), which is 122 m above sea level.

[2] O Pui Tong (澳背塘) is a bay surrounded by the crook-shaped Crooked Island and Yeung Chau.

[5] O Pui Tong, together with the northwestern waters of Kat O, are two of the 26 designated marine fish culture zones in Hong Kong.

[8] During the Ming dynasty, a decree required all inhabitants to leave the island.

[11] Kat O has been part of the Plover Cove (Extension) Country Park since 1979.