Good to see these pictures. Having spent my (very) early childhood days there, and just visited for a couple of weeks a few months back, I can attest to the vast and rapid development of the country. Just to give you an idea, this is Gangnam in the 60's, made popular by the song everyone's heard a million times:
And now:
It may not seem like a big accomplishment, but given Korea was a war torn country in the 60's, it's quite a feat (and of course, lots of sacrifices made this happen).
It was a fun place to visit (again). If you're in Daegu, you should check out Gyeongju which is just a few clicks to the east. Very touristy, but lots of history there. Get the famous bread (sold in shops literally on every street. Traditionally, you must bring back bread for your neighbors/friends if you visit.). Also, Jeju Island is a good place to visit, just off the southern tip of Korea. And SIM (Samsung Innovation Musem) is a cool place you can play with all of their high-tech stuff (in Suwon).
Food wise, lots of western restaurants there (with an eastern twist to the menu). Open markets are great places to get some good Korean food, though. Probably most unusual is going to be silkworm larva. Back during the war, with no meat available (affordable), this was the cheapest way to get protein. My wife tried it, surprisingly. Doesn't taste bad, but pretty gross knowing what it is. You won't really find anything too exotic, like scorpions, rats, etc. Maybe freshwater octopus (live and whole).
Have fun there. I miss it already.
EDIT: Well, I don't know how to make png's work here...