This is 99% invisible.

I'm Roman Mars.

Cities like living things evolve slowly over time.

Buildings and structures get added and renovated and removed.

And in this process, there are bits and pieces that get left behind.

Little vestiges.

Humans have tailbones but no tails.

Whales have pelvic bones but no legs.

And cities have stairs that lead to nowhere.

Telephone poles without wiring and pipes that carry nothing at all.

That's producer Avery Truffleman.

Most of the time, these architectural leftovers rust or crumble or get taken down.

But other times, these vestiges are not removed and they remain in the urban

organism. And sometimes, even though they no longer serve any discernible purpose whatsoever, they are actually maintained.

They get cleaned and polished and repaired and repainted just because they're there.

These architectural leftovers first caught the attention of an artist in Japan

named a Casagawa Gienpe.

This was in 1972.

One day, he was on his lunch break with some friends and as they were walking to lunch they came across this staircase

That went up and then back down, but there was no door at the top. He basically just walked up and then walk back down.

And there was a piece of the railing that had been recently fixed.

Something clicked with him when he saw that.

...