Venice would be your major example!

It was build on a malarial swamp in the late classical and early medieval era and is still to this day still built on a lagoon. Which is why it is sinking...

Martin, John Jeffries, and Dennis Romano, eds. Venice Reconsidered: The History and Civilization of an Italian City-State, 1297–1797. JHU Press, 2002.

There are tribes of Shiites in southern Iraq that live in swamps and marshes. There are also groups of people that thrived in the swampy marshes of the Mekong Delta in vietnam. Nigeria also hosts swamp tribes.