The mystery continues as another monolith has been discovered, this time, in a Dutch nature reserve. Business Insider reports that on Sunday morning, a group of people on a morning stroll came across a towering metal structure covered in ice and surrounded by a small pool of water in the heart of the Kiekenberg nature reserve. The walkers were baffled about how it got there because there were no visible footprints near it, reports the Dutch paper Algemeen Dagblad and while some people have playfully toyed with the idea that the monoliths are proof of alien life, locals suspect it is just a prank.