So simple it's genius: Gambia's voting system uses marbles and bells to prevent people from voting more than once:
Voters enter a booth and pop a clear glass marble into one of three drums representing the candidates, instead of a putting a ballot paper into a box.
As the marble falls into the drum, it hits a bell so officials can tell if anyone votes more than once.
It's a unique system introduced in 1965 because of Gambia's high illiteracy," Gambia's chief electoral officer Kawsu Ceesay told the BBC.
The bell resembles a bicycle bell so bicycles are banned from around polling stations to avoid any confusion.