Cuba's earliest known human inhabitants colonized the island in the 4th millennium BC. The oldest known Cuban archeological site, Levisa, dates from approximately 3100 BC. A wider distribution of sites date from after 2000 BC, most notably represented by the Cayo Redondo and Guayabo Blanco cultures of western Cuba. These neolithic cultures used ground stone and shell tools and ornaments, including the dagger-like "gladiolitos", which are believed to have had a ceremonial role. The Cayo Redondo and Guayabo Blanco cultures lived a subsistence lifestyle based on fishing, hunting and collecting wild plants.