Seoul certainly does have its fair share of alien megastructures, and nothing demonstrates this more than the Dongdaemun Design Plaza. This is a stadium-sized plaza (it literally replaces a stadium) that contains an other-worldly building, design museum, and other art things.
I was expecting it to be nothing like the photos I’d seen on the internet and it wasn’t – it was better. You get spat out of your taxi on the edge of an angle-defying building, and are free to wander around in awe. When you find an entrance portal you are sucked up inside to vast endless slopes that seem to go nowhere. As you proceed further into the depths of the ship you eventually slot onto the conveyor belt that takes you to the processing plant for reassignment. The alien overlords nod with contentment.
Or something like that. It was nice.