At the beginning of the tour, you're given a sticker to identify your group so nobody can join the tour in progress as it crosses streets aboveground. This post, right in front of the gift shop entrance, has become a conspicuous place to leave the stickers at the end, perhaps because afterwards, it's good for a two dollar microbrew at the bar owned by the people who run the tour... if you haven't stuck it to the pole.
END OF TOUR
