We did a nice variety of things, from crazy markets and temples, and natural beauty (mountains close to seoul), and we even rented a car to experience korean traffic jams first hand.. good fun.
Did I say markets? For me, one of the craziest things about seoul is the shops here. Think of any specialized item, say, um, toothbrushes, electric plugs, paint, whatever, then imagine a shop 3x3 meters (10x10 feet) jam-packed with just those items... then imagine several dozen stores in the same street right next to eachother mostly identical... it is quite surreal. The prettiest I found one street where tons of small shops sold and produces gears and other other mechanical items... a nice composition of fotos I took from all those shops forthcoming, I'll include a single sample below.