Knowth

Knowth, in Irish Cnobha, is a place where there are Neolithic tombs. Knowth is one of the ancient monuments of Brú na Bóinne, which is situated to the north of Dublin. It's an amazing place because not only is it a UNESCO World Heritage Site, but also because the tombs were built thousands of years ago, with reasons that still aren't very well understood, complete with symbols, and a deep knowledge of astronomy or the operation of the sun and stars. That's because this place is intended to let the sun at a particular time of year and other details that scientists have gone to great pains to explain, considering improvements in the "technology" of the time.