Busan is the best success story I know for the Avent-Yglesias approach to urban density. Imagine taking a city that looks like San Francisco, or more concretely Nagasaki, and letting millions of Koreans in to live there.
They served me the live, still-wriggling and squirming sea worm entree, which you are supposed to dip into sauce and push down your throat; it was neither the best nor the worst course of the meal.
White sashimi, dipped into hot bean paste, is the preferred manner of eating raw fish here; tuna, salmon, and eel are not popular.
On the beach, on a clear day, you can see Japan across the water.
In a nearby rural area, the populace would appear to go to Sunday church, dressed up in their finery, and then hang out at the museum and welcome center for the local nuclear power plant.
A day tour of Hyundai City, the special economic zone, the chemical-industrial complex (reminds me of New Jersey), and the new port is better than a day tour of Korean temples. They are all targets for North Korean missiles.
The people I have asked predict reunification within ten to fifteen years. They are ashamed to have such a brother in the family.
If you visit Korea you should come to Busan.