There's actually quite a lot going on in London to do with Korea. Well, of course there is, it's LONDON! London has everything, because London is magical and amazing. If you think there's something you can't find in London, it's just because you haven't found it YET. But I guarantee it exists, whatever it is.
The place to go if you're in London and interested in Korean culture is the Korean Cultural Centre (KCCUK, 한국문화원), on Northumberland Avenue just by Trafalgar Square. They have a library and an art gallery, and also organise a number of cultural events on and off site, which you can find out about on their website or by popping in. KCCUK is also home to the Sejong Institute (세종 학당), a weekly Korean language course. This is a brilliant course, and I took a semester there when I was back in London for a few months last year. What's more, the course is free! To enrol at Upper Elementary (actually I think they call it 'Beginners 2') or Intermediate level, you'll need to take a placement test on a designated day, but for the Beginners level course there is a lottery system for enrolment, as unfortunately they do not have enough places for everyone who applies. So watch out for the application window, and good luck!
There's also the London Korean Film Festival, which is currently showing films every Thursday evening. I went to see last week's movie at the Apollo, which was a free screening followed by a Q&A session with the director. Although not quite all the seats were filled, the event attracted a diverse range of people and it was a big enough audience. It would be nice to see even more people going to the screenings - after all, it's free!
Summer is a good time for Korean culture in London because there's the 'All Eyes on Korea' 100 day festival, which has a broad programme of events ranging from pop music to educational lectures. That's happening right now and will continue until the middle of September, so again check the KCCUK website for details. It will also include a two-day event in September as part of the Mayor's Thames Festival, which will have a bunch of stuff going on by the south bank. I went to it a couple of years ago and they had some information stalls set up and a stage with some B-boys, a taekwondo demonstration and some kind of weird theatre piece, as I recall. Oh yeah and beer.
Of course, I've got to mention London's Korean food. This seems to be on the up, because when I left the UK last time there was a new restaurant in Holborn called Kimchee, and when I went back there the other day I saw a queue outside the place - at lunch time! So that's cool. Because it was so crowded we skipped it and went to Asadal instead, which is a restaurant just by Holborn station and it's been there a while. The food was pretty good. There's also a cute canteen-style place by Centre Point, as well as a Korean grocery store that does great freshly prepared banchan, and another Korean grocery store by Chinatown. In fact there are quite a few Korean restaurants dotted around central.
I'm also aware of an actual 'Korea town' further out in New Malden (where?), but I've never been there myself. Well, I looked it up on Google street view but for some reason it freaked me out a bit to see a bunch of Korean places nestled amongst the bookies, chip shops and estate agents of suburban Greater London. It just seemed like some kind of nightmarish culture clash to me and I can't really explain why! Of course, that's not to say you shouldn't visit, though.
Is there a noraebang in London? Yes, there's a Korean karaoke place above Corean Chilli on Charing Cross Road by Chinatown, and a number of other private Karaoke places that are billed as 'Japanese style' but are the same thing anyway, I just don't know if they have any Korean songs. Maybe not.
One more thing, I get quite a few hits on this blog from people searching for a Korean spa or jjimjilbang in London, so I tried to look through some Korean language info on the net to see if I could find one. Ok, well, you know when I said you can find anything in London? Yeah, well ... That might be a bit of tricky one. Of course there are loads of day spas, hotel spas, saunas and leisure centres, I just don't know of any specifically Korean spa in London ... yet. Your best bet to get a similar experience is probably at one of London's Turkish hamams, so search for that instead!