Not sure if this is the right forum to discuss this, but at least a UK group will understand UK geography :)
Facebook is in a right mess as far as it's list of places that people can select to use as location markers. http://www.jasonfriend.me/facebookplaces/w/editing:incorrectlyspelledcities:... will give you some idea of the extent of the problem, and that is by no means complete. You will notice that Wikipedia links are used to provide background information and basically prove to US edtors that we know what we are talking about, but the wikipedia page names are ow causing problems as they are being taken 'literally'.
Example https://en.wikipedia.org/wiki/Harlington identifies three UK locations, but uses 'London' rather than 'Hillingdon' to identify that page. As soon as one is on the page the Hillingdon connection is listed, but Facebook are making a meal out of things which is creating even more of a mess.
While it is not a wikipedia problem, one tidy up that would make things a little more consistent across several directories would be to replace many of the ,London disambiguation with the correct borough and then the crude Facebook processing would at least pick up the right cross link without having to mess up the hierarchy in Facebook. Personally I'd prefer it if Facebook used a better method of listing places, but many of these problems go back several years and we have not been able to get any movement, so fixing the other end first may finally prompt some action :)
( And I do not have any problem undertaking the work. I've got most of the problem links already documented as part of the 'fix Facebook' campaign )