If you could have an all-expenses paid trip to see any famous world monument, which monument would you choose?

A 'world' includes the planet and all of its associated parts. Plants, animals, atmosphere and I would argue the moon. The moon does not exist in any context outside of this world, so I'm going to allow it. :) If it had said planet, I'd agree, but world is just vague enough that I'm demanding to see the flag.