Take the tour of the night time sky… in English and learn about the Southern skies—do not miss this!!
Take the Valle de la Luna (Valley of the Moon) tour at sunset—there is a volcano in the distance which is where Bolivia, Argentina & Chile meet!
Take the geyser tour before sunrise (freezing cold, but an experience—especially if you take a dip in the hot baths!)

YOU MUST GO SANDBOARDING!!!!!

You can get these tours by just walking around San Pedro and stopping into booths. A few were offered thru our hostel (3 tiered bunkbeds with a thatched roof!)