Swiss photographer Willy Spiller lived in New York during 1970s, and was passionate taking photographs of city’s subway system.

His book Hell on Wheels is a look inside his rich photo archive, delving into the underbelly of New York during this pivotal time.

“Willy Spiller’s images are as much a visual document of this incomparable realm as they are a syncopated, colorful poem to the city of New York and its people,” shares publisher Sturm & Drang.

Below, via MyModernMet, take a look at some of Spiller’s photos.