Worried about their future, island nations like the Maldives or Fiji raise the alarm every year during the environment summit COP 23 on the impact of rising sea levels. But for small islands, it's the past they're worried about, and watching their history wash away.
Unesco's first world heritage site in Africa, Gorée Island off the coast of Senegal, was the largest slave-trading centre on the African coast. Today it's facing severe erosion and human-built defenses such as seawalls can't hold up against the elements.
Unesco says renovating world heritage sites is complicated but not impossible.
Faced with few options residents on Gorée are working to make their island as sustainable as possible.