The Dolmen of Menga is a megalithic burial mound called a tumulus, a long barrow form of dolmen, dating from the 3750-3650 BCE approx. It is near Antequera, Málaga, Spain.
It is one of the largest known ancient megalithic structures in Europe. It is 27.5 metres long, 6 metres wide and 3.5 metres high, and was built with thirty-two megaliths, the largest weighing about 180 tonnes. A very rare singularity, in megalithic buildings, is the presence of a deep and narrow well in the bottom of the chamber. It presents in the first orthostat of the corridor a series of anthropomorphic engravings in the form of a cross as well as a star.
Wikipedia https://en.wikipedia.org/wiki/Dolmen_of_Menga
Address 29200, Spain
Coordinates 37°1'27.074" N -4°32'53.706" E