Apparently it is a worldwide thing and has a history - https://en.wikipedia.org/wiki/Hash_House_Harriers
It's a real club with formalities. We met at someone's house, whoever is hosting that month, and our club usually divides in two groups, the walkers or the runners. We all head out and look for clues in chalk on the ground or on poles, which are arrows and circles and other marks to indicate the trail. The designated people that mark the trail are called 'hares'.
|photo from Merida hash group - walking in Centro|