Step out at the Oxford Circus stop in London and your ears are immediately assaulted by several different languages at once. That's understandable, considering Oxford street is usually quite crowded—tourists and Londoners alike buzz in and out of the shops and restaurants the street is known for.

One of the languages I heard most in that region was French. I thought this was because, in general, London has the most French nationals living there of any other city outside France. A more targeted review shows it's also because a lot of French speakers live in that area.

Linguistic diversity is one of the most striking things about London. If you're like me and enjoy the playing "What Language Are Those Strangers Speaking?," this interactive map can help inform your guesses. Around the Shoreditch High Street, for example, it's pretty likely that you're hearing Bengali.

Oliver O'Brien, a researcher in the geography department at University College London made this map using 2011 census data after being inspired by a colleague's map. "The map shows a less random and 'noisy' pattern of languages," he says.

Clicking on a station pulls up a breakdown of what languages are spoken for output areas within a 200 mile radius. The bubbles are color-coded for the language most widely spoken after English—the bigger the bubble, the bigger the proportion of people that speak that language.  

English is the most widely spoken at most stops except five. Less than half of the people around Southall, Alperton, Wembley Central, Upton Park, and East Ham speak English.

So which stop wins the prize for Most Linguistic Diversity? It's the Turnpike Lane stop on the Piccadilly line. There are 16 different languages spoken around that area, and none of them are dominant (except English, of course).

The most homogenous stop is Theydon Bois on the Central line, where 98 percent of residents speak English.