The stone wall at the entrance of Theopetra Cave in Greece is the oldest ruins in the world – it is believed to be the oldest man made structure ever found. പുരാവസ്തു think that the wall may have been built as a barrier to protect the cave ' s residents നിന്ന് തണുത്ത കാറ്റും at the height of the last ice age. Theopetra ഗുഹ ആയിരുന്നു ആദ്യ excavated in 1987 and നിരവധി artifacts have been found at the site. അത്തരം ഫ്ലിംട് and ക്വാർട്ട്സ് ഉപകരണങ്ങൾ, animal bones, and jewelry from deer teeth. Additionally, there is റേഡിയോ കാർബൺ തെളിവ് that people inhabited the cave for nearly 50,000 വർഷം, covering the Middle and Upper Paleolithic, the Mesolithic, the പാത്ര ശിലായുഗം, the Pleistocene, the Holocene periods and beyond.