As to my surprise, there are still some hidden tresasures on the underground network.
I wouldn't have a clue about dummy houses if it wasn't for my dad. When he visited me in London, he mentioned that there is a place in the city, where there are fake houses built for the purposes of the tube network. To find out what he was talking about I had a quick look on Google – and wrote "fake houses London tube" and what appeared to our eyes was all the urban research about so called "dummy houses".
The only remaining one is located in Leinster Gardens 23/24 in Bayswater, near Paddington Station (currently on the District Line). To be precise those houses are not houses anymore. They are only facades, because the rest of the buildings were destroyed for the use of the underground network. When that mean of transport became in use, trains were powered by steam engines. Those had to vent the steam at some point of their journey, in order not to leave the smoke in the tunnels, but it was difficult while most of it was done underground. Therefore, in different places around the tube network, engineers had to make the steam vents in the place of the houses. I couldn't find information on whether the houses were already there when the underground was built or the façade were erected only for this purpose (to cover not the most beautiful hole in between two real houses) but either way it is an interesting fact about the London underground network and not so well known as ghost stations.
Spot the difference; picture by Joanna Sopylo-Firrisa
If you don't know that the houses are actually only a façade, you may not even notice that there is something wrong with them. The front of the fake one looks exactly the same as that of the real one, with only some differences which are to be spotted when you look closer – the windows are painted, there are no mailboxes or door handles. On the other hand, if you notice that there is something wrong with the house but do not know their history, you may invent your own story, e.g. something terrible must have happened inside and the house is not in use anymore. As the urban story tells, one "gentleman" even sold 10 guinea tickets for a charity ball at Leinster Gardens in the 1930s, getting a little fortune thanks to it and leaving dressed-up guests knocking on the doors expecting to have great fun.
Fortunately we now know that the place is not a real house at all and have a pleasure to look at it, see it from the back and think what a great surprise was left by late 19th century engineers for 21st century treasure hunters.