The Cromeleque dos Almendres is a neolithic stone circle about 15km west of Évora, tucked into a cork oak forest on a gentle hillside above the plains. It is one of the oldest megalithic monuments in Europe and arguably the most impressive in the Iberian Peninsula — a roughly oval arrangement of 95 standing stones, some over two metres tall, covering a hillside the size of a football pitch.
Unlike Stonehenge, which requires you to view it from behind barriers, the Cromeleque allows you to walk among the stones in complete solitude (the site gets surprisingly few visitors). The cork oaks are spectacular, and at dawn or dusk the stones glow with a warm orange light. On the way from Évora, stop at the Menhir dos Almendres — a single standing stone about 1km before the circle, carved with symbols, that gives a sense of the broader megalithic landscape this region contains.
Getting there requires a car; the access road is not served by public transport. The surrounding countryside along the CM1075 road is beautiful driving and gives a good sense of why the Alentejo plateau is one of Portugal's most distinctive landscapes.