We did a very touristy thing: We visited Hobbiton, otherwise known as the Shire, from Tolkien's writings of the Hobbit and the Lord of the Rings trilogy. (More specifically, the extra-length movie(s?) from Peter Jackson.)
It's quite photogenic, though I didn't set a new record for photos in a day (current record: 1077 photos!). Overall it was a good experience, though definitely very pricey (NZ$75 for a 1.5 hour walking tour and a local beer). Great for superfans, and for those who like cute spaces. Mild fans, and those who haven't seen the movies might skip this one in favor of another of New Zealand's amazing experiences.
The tree on top of the hill (on top of Bilbo’s hole) is completely man made. The one used in the same spot in Lord of the Rings was original to the hill, and real. But when they came back to this site to shoot The Hobbit movie a few years later, they needed a tree that looked 60 years younger.
The hobbit holes (houses) are all various scales to use with the different characters (humans appear large by the holes, but hobbits feel right at home; use different holes/sets in different shots!).