Having just returned I have a few thoughts as a first timer -

I was there for a week. The public transportation system is amazing, - extensive and cheap. It's a little bit daunting and slightly confusing at first. I stayed right next to the Hongik Univ stop which made using the airport train very convenient. Careful study of the options led me to use the Korail trains instead of the subway on a few occasions including using the airport train. Since the fare is all the same and you use the same card it's all very simple. As a bit of a transport geek I totally loved it. The stations are often huge with tons of exits and transferring between lines can mean lots of escalators and walking, but signage is extremely well done.

I was a little bit surprised how little English is spoken especially in what I would have thought were big tourist areas. I spend a lot of time in SE Asia where communication with English is fairly easy. At least signage is in English in most places.

I only ended up visiting one palace as they all seemed pretty similar. I bought the pass that gets you into all of them since it was so cheap (10000 won), but in the end only used in one place. I left it at the Airbnb in case some one else could use it since it's good for 3 months.

Seoul N Tower was a little disappointing. Partly that was due to the haze in the air which really limited visibility. I probably should have gone later in the day.

I did visit the new Lotte World Tower observation deck which opened the day before my visit. Rather expensive, but I am a sucker for those things. Again it was pretty hazy but once it got dark the city lights view was OK. The windows were pretty filthy on the outside though which made photos even more difficult. Not sure it was worth 27000 won.

The cherry blossoms were just getting started around Seokchon Lake so that was a nice sight in the same neighborhood as LWT. Some nice night time photos with the tower reflected in the lake.

Dongdaemun Design Plaza was awesome and probably my favorite place. It was like visiting the future. Lots of great photos there. Too bad the building's pretty much empty on the inside.

Tons of cops downtown. There was a big pro-Park demo one day so the police with shields and riot gear were out in force including the subway stations downtown. It was a little disconcerting.

The National Museum is great and free for the permanent collection. I went there on a rainy day for a few hours. There's a tunnel almost the entire way from Ichon station to the museum. It was nice to learn a bit about Korean history. The collection has enough interpretation in English.

The whole city seems to be composed of coffee stores, convenience stores and steak houses. I was also surprised that the shopping mall concept as practiced in other places seemed foreign there. Having just spent a week in Bangkok which is nothing but shopping malls it seemed odd.

All in all I really enjoyed the city. Did a ton of walking.