 Archaeological excavations conducted over a period of years in the latter 1900s have revealed evidence of bear, marten, seal and porpoise, but also elucidate Mesolithic hunting and gathering technologies through discovery of bone spears, elk antler harpoons and flint.These earliest inhabitants would have crossed the Kalmar Strait from the mainland toward the end of the last Ice Age, before the glacial cap had fully melted, and thus provided an ice bridge.The settlements of the Stone Age are key resources on Öland that led to the UNESCO designation of the Stora Alvaret as a World Heritage Site.