Riding the up escalator from Marylebone underground station (<a href="https://en.wikipedia.org/wiki/Bakerloo_Line" class="extiw" title="en:Bakerloo Line">Bakerloo Line</a>), London, England, to <a href="https://en.wikipedia.org/wiki/Marylebone_station" class="extiw" title="en:Marylebone station">Marylebone railway station</a>. The beeps near the end are <a href="https://en.wikipedia.org/wiki/Oyster_card" class="extiw" title="en:Oyster card">Oyster cards</a> being swiped
<a href="//commons.wikimedia.org/wiki/User:Pigsonthewing" title="User:Pigsonthewing">Andy Mabbett</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>