This 150m-tall Songdo landmark has sensational 360° views from its IFEZ Observatory on the 33rd floor. From here you can see just how many empty city blocks there are left to fill, as glossy propaganda videos espouse the project's success. It's located on the north-west edge of Central Park.
If you're hungry, there's a good, usually quiet Japanese restaurant a floor down from the observation deck. Handily, G-Tower's lobby has ATMs and a convenience store.