One of the must see stops for London Underground buffs is the disused Aldwych Tube Station. All services to the station ceased in 1994, but TFL through the London Transport Museum still run periodic tours. However, they aren't cheap. Full price tickets are £20 with concessions getting a massive £2 discount.
So is the tour worth £20? Well that depends on how much you like the tube. The video above comes from reddit user zzpza who visited on December 1, 2012. It gives you a good idea of what you can expert to see. zzpza adds that:
I took photos on the way down and video on the way up, so the video is only the way out from the second platform. The other platform had test tiling (test design) in a small part of it, some old advertising, an old tube map and a train from around the 90's. I also didn't record much from the entrance or ticket office. So there was more to look at. You were pretty free to wander as long as you stayed near the tour guides. We didn't get to see any of the 'non public' parts of the station, but I have seen photos from other tours that have.
If Aldwych Tube Station is something you'd like to visit, make sure you head over to the London Transport Museum website to find out when the next set of tours are taking place.