England’s Stonehenge may be the most iconic of megaliths, but that doesn’t mean it’s unique or the oldest. In fact, when it comes to age, it certainly isn’t. The Cromlech of the Almendres in Portugal is much older. This is considered to be the best example of Neolithic structures in the Iberian Peninsula and one of the best in Europe.In the United Kingdom, Stonehenge isn’t even the oldest there. In fact, some of the oldest sites known today are in the far north in remote islands off the coast of Scotland. There in the Orkney Islands, the Skara Brae Prehistoric Village preserves a village and megaliths that predate Stonhenge.
Source: This ‘Stonehenge’ In Portugal Is Even Older Than The U.K. Site