The reasoning was that every climbing gym has some bouldering, so I did some searching online only to find this website: http://www.indoorclimbing.com/spain.html that listed very few climbing gyms in Madrid, only one of which was easily accessible by the metro (and therefore my monthly metro pass), so I decided to check it out today after work.
Getting to Bulderking required me taking the Circular line of the metro that I'd never taken before, only to end up in a much poorer neighborhood of Madrid, very clearly not touristy, very clearly filled with local madrileños.
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As you can see, to get there I basically had to cross the entire city. It's alright - I read my book on the metro. Getting out of the subway, my map not reaching that far into the south of the city, I was recalling from what I had seen on Google Maps for guidance. The place's website says this is what to look for:
Don't know about you, but looks a bit sketchy to me. You have to ring the doorbell all the way on the right through a glass shield for someone inside to ring the buzzer and let you in.
The place is super chill - all bouldering, over every wall and ceiling. Plenty of overhangs (which I definitely don't have the strength to do quite yet). The total size is about three times the size of the MIT bouldering wall. There is chalk, a small collection of shoes, some weights/machines, and some space for stretching. When I got there at 19:30 there was a class going on, and the owner was nice enough to explain to me the fact that an entrance costs 6 euros, but if you get a bonus pass of 10 entrances, he'll charge you 45 euros, which makes 4.5 euros for an entrance. He also said to call to see if they were open, since it is just him working the gym, and that he's not open Fridays.
There aren't that many placed routes, and people just do what they want to construct their own routes. I thought this would be easier, but I found myself making up problems that were both fun and challenging for me. All in all, I love bouldering.
I think I'll try to go at least once a week, since I feel like I need some arm strength. After an hour of climbing, my fingers and forearms hurt; clearly I need to practice more.