Stonehenge, the UNESCO World Heritage Site and prehistoric monument in Wiltshire, consists of a purposefully arranged giant circle of rocks, some weighing up to 45 tons. The origin of Stonehenge remains a mystery to this day. Many believe people gathered there for religious ceremonies and funerals, others think it was a healing ground, and some believe it was used as a temple for sun worship. While archaeologists believe the site may have existed since 3000 BC, there are endless questions as to how this architectural feat could have been accomplished with few modern tools. An intriguing hypothesis is that Stonehenge was actually the work of aliens. However, scientists have debunked that theory. Regardless, this mysterious architectural phenomenon is truly one-of-a-kind, and definitely a bucket list destination!