Reminds me of the Alternate Reality Game, Perplex City, from around 2006. There was a metal cube buried somewhere on earth with a £100,000 prize and lots of fun

Reminds me of the Alternate Reality Game, Perplex City, from around 2006. There was a metal cube buried somewhere on earth with a £100,000 prize and lots of fun puzzle cards for clues. It was eventually found in England, but one of the cards was only solved recently: https://www.wired.co.uk/article/perplex-city-satoshi https://www.wired.co.uk/article/perplex-city-satoshi I imagine a lot of other HNers played too!