Get lost in some woods.
DEFINITELY. This is one of the best things you can do when high. You'll come across all kinds of shroom species, and it's just so crazy...this is probably my favorite place to go when high. take a bb gun and shoot shit.

Video games are also great. me and a friend play Perfect Dark and old school video games, we have a blast.

Also...get high...literally. Climb on top of your roof, or climb a mountain (ive done this several times...can see for miles and miles, its incredible) It's really great to smoke up at the base of a mountain, "trip" through the woods, climb to the top, smoke again, and enjoy.

if you play any musical instruments, rock out. that's fun to do too. oh, and rollercoasters definitely. i've done that before too, its out of this world.