Koidu Town (or Sefadu) is the capital and largest city of the diamond-rich Kono District in the Eastern Province of Sierra Leone. The population of Koidu Town is 124,662[3] based on the 2015 Sierra Leone national census. Koidu Town is the fifth largest city in Sierra Leone by population, after Freetown, Kenema, Bo and Makeni. Koidu Town is a major urban, business, commercial and diamond trade center. Koidu Town lies approximately 280 miles east of Freetown, and about 60 miles north of Kenema.
Two of the world’s ten largest and most famous rough diamonds were found in the Woyie River that flows through Koidu Town.The city is officially known as Koidu City. The mayor of Koidu City and members of the Koidu-New Sembehun city council are directly elected every four years by the residents of Koidu. The current mayor of Koidu Town is Komba Sam of the Coalition 4 Change political party[4].