Bal Bhatla’s fascination with metro systems began in early 2011, around the same time he discovered Instagram. He loved the app, but didn’t know what to take pictures of. His time-consuming job didn’t leave much time for photography, so he decided to turn his camera to his commute.

Known as “Mr. Whisper” on Instagram, Bal makes sure to experience local transportation systems when he travels, and thus has photos from London, Paris, Rome, Seoul, Tokyo, Sao Paulo, and New York City in his repertoire.

For Bal, this kind of street photography is all about documenting the present — the now, as he puts it.

“When people look at my work, they can relate to the various situations that unfold on the metro everyday, and it evokes a sense of nostalgia,” he says.

He hopes that if someone were to see his photos in 50, or even 100, years, they would gain a little bit of insight into life underneath the cities of the early 21st century.

You can find Bal’s photos on Instagram, and more of his work on his website. Stay tuned for more of Bal’s metro photos next month.