So just what it number 12? That’s the question currently flummoxing Londoners obsessing over a Tube station emoji quiz.

The quiz that contains the names of 13 Underground stations represented as symbols has been widely shared on Twitter and commented on around other social media such as Reddit since yesterday.

This Is Local London:

Number 1 is Water + loo = Waterloo, number 2 is Angel ... you get the idea.

While 12 of the 13 riddles have proven relatively easy for people to decipher, the clues at number 12 have got everyone stumped.

Loads of theories have been flying around, such as it being a bus replacement service, Canary Wharf or Barbican.

Some have suggested it might be a mistake or a deliberate red herring.

So far settling on a definitive answer everyone can agree on appears to have eluded the world wide web.

Have a good look and see if you can figure it.

Of course, we’re really brainy here so we got the correct answer to number 12 straight away.

But we’re not going to tell you what it is because that would spoil all the fun.

That’s our excuse and we’re sticking to it.

If like us you've worked it out and feel like sharing your answer, post a comment below or tweet us @local_london