which one is castle again? it's not the capture point one with the wide open spaces?

This is cp_castle.



This phase only has one cap point, which a scout can run to in about 12 seconds. The attackers' spawn is to the offscreen to the left. This area is a sniperfest, but will invaribably end up with the attackers and defenders bottlenecking at the opening under that big tower on the left, for some reason.



This is the cap point (above), the defenders' spawn room is right at the base of these wide stairs. If the defenders manage to get three turrets and a pyro on the point, it's very unlikely that the attackers will crack it. One demo man can plant a ton of charges on the far steps and blow an ubering medic out of range. The near steps are so close to the defenders' spawn that you can't really uber past em without getting shot to hell in the back once your uber runs out.



This phase has two cap points. This is the second (above). There is no screenshot of the first cap point, but it's not very far away. This is the level where the attackers have only one way out of their spawn, down a long, cover-free staircase that turns into nothing but a meat grinder. If you can uber past the meatgrinder, the defenders almost always lose. If not, you'll never get the first cap point. It's either over in like thirty seconds or it lasts the maximum possible time, because the second point is practically indefensible. Scouts, soldiers, and demomen can jump or bomb-jump right up to it and it's a very short distance from the first cap, so a successful push on the first almost invariably takes the second immediately. The main problem is that the defenders can't get to it if the attackers have taken the first point, because they have to come around the wall on the left and the attackers almost certainly already control the space if they have the first point.



This is the first cap point of the final stage. I'd say this stage was the best-designed part of the map, except it always seems like it gives the attackers like half an hour to cap the points, which gets incredibly tedious.



Above is the final cap point of the final stage.


These comments are all just my inexpert opinion, but I'm not a huge fan of this map.

I actually enjoyed castle despite me only playing it once, I got 4 backstabs in a row one after the other.... grand!