Its a bit unfair to not join Dunedin into the main thread of Otago, however, as I spent many years here studying it is hard to describe the different things available without making it a bit of a long thread that would make Otago far too long for most readers.
The top 10 must see things in Dunedin:
1. Baldwin St - The worlds steepest street. Every year there are various acitivties that involve usually running up and down this st for a goal of fundraising usually. There is also the Jafa rolling comp, which is quite amusing to watch.
2. Penninsula - The surrounding bays of Dunedin Penninsula are quite amazing. There are seals and yellow eyed penguins that you can see, and experience some amazing beauty.
3. Albatross - At the head of the Penninsula, Dunedin is home to an Albatross colony. The drive out there is also worth it as you get to travel through some great penninsula area and see the Quarantine Island (where the immingrants to NZ all had to wait 6 weeks to ensure they didn't bring diseases on land).
4. Railway Station - The architecture of the railway station is quite amazing and when it was built, was ahead of its time in structure. It is also a great place to get to start the gorge railway journey to Middlemarch, which is a definite must do.
5. Cadbury Chocolate Factory - highly amusing to see how all the candy is made, and taste a bit at the end. It is advised to eat beforehand as the smell of the choc, can make one very hungry by the end, usually resulting in binging.
6. Speights tour - before Auckland sadly took over the main production of the Speights Beer it was made in Dunedin, in a very historic brewery that is one of the last remaining of its kind in the world (gravity feed system). It smells good, and you learn a lot about the production of beer. Not to mention that at the end there is a very good tasting session.
7. Lookout - At the top of the North East Valley hills is a war memorial and look out over all of Dunedin. Great place to watch the sunset over the whole city and surrounding penninsula.
8. Octagon - The lovely Octagon is the centre of the old Dunedin with lots of shops on it today, and a number of eautifu lold churches on or very nearby it.
9. Beaches - Despite being a bit nippy, the beaches in Dunedin are not only a great place to swim but also area quite historic. It is possible to see clearly the dykes construction holding back the water that would otherwise see South Dunedin township completely disappear.
10. University - Obvious the oldest University in New Zealand is a must see. The beautiful old buildings from the Old Block are in great condition and the ever expanding campus with its Scarfie students is a great place to live and learn.