I found Gyongju to be a pleasant place to be based during my first few days in Korea. Some guidebooks seem to go over the top with their praise of the place which can leave people disappointed with the reality, however for me it was a great place to relax and see some of the most important sites in Korean history.
On the bus to the city I got a great introduction by listening to this episode, from the British Museum/ BBC A History of the World in 100 objects. On top of this I visited the free Gyonju museum which was very interesting although a touch over run with friendly school children practicing their English on me. These gave me a better understanding of what may otherwise just be a series of grassy hills. I have actually visited a fair few grass mounds in my pursuit of World Heritage Sites but these were the most enjoyable I have so far encountered. The central cluster are actually a very enjoyable piece of landscape design and are very well presented, also there is one tomb open for you to explore the interior, which is well worth a look.
There are two other WHS nearby and whilst the modern town is decidedly unremarkable, it has all the amenities you will need making this a great place to be based in the south of the country.
[Site 6: Experience 10*]
* A note to explain the top marks for the experience at this site, it isn't necessarily for the wondrous things you can do in Gyongju. It is actually for the astonishingly friendly welcome I was afforded everywhere I went in Korea, but especially in this city. If you have read reviews of the Korean world heritage sites on this site and thought that perhaps Korea isn't really the most interesting destination then I would implore you to not be put off a visit. Whilst its WHS are nice they are not perhaps in the highest order; however the people, food and atmosphere are magnificent. I have posted an example of the incredible hospitality I received here.