Hunters of puzzles may want to take a look at "Pablo's Armchair Treasure Hunt" at
pablosath.com. This is an annual puzzle-hunt sort of thing -- lots of interrelated [enigmatic-puzzles], leading to the location of an actual physical Thing to find somewhere in the UK. A good team typically takes a week or two to solve everything, though I can't help wondering whether @Deusovi's gang might embarrass everyone by doing it faster.