Love in London: She proposed on top of the O2 arena!

London is a city of nine million people, and love blooms all across the capital.

Every week Salma El-Wardany speaks to a different London couple about their love story. How they met, where, when, and what it all means to them - and we'll also hear some music they've chosen that's been important to their relationship.

The week we're meeting East Londoners Sarah and Daniel, whose whirlwind romance is inextricably tied to one of East London's most iconic music venues - the O2 arena.

It started INSIDE - with a first date at 50 Cent concert. But then took some lofting steps forwards OUTSIDE the venue, with Sarah popping the question on top of the O2's famous domed roof.