There are a few articles and a bunch of blog posts which talk, often full of factual errors, about an interesting phenomenon that happened in the late1960s and early 1970s at US Airports. It was an idea put forward as a way to add more takeoffs and landings without having to buy or fill land for new runways. The approach was referred to as STOL (Short Takeoff and Landing). While this concept is still used in places where longer runways are just impossible to build, the idea never took off (pardon the pun) at large commercial airfields. But, for a few years, several large commercial airports constructed comparatively tiny runways in and among their existing large ones. These small runways allowed specially equipped small passenger planes (like the DASH-7 and Twin Otter) to take off and land using a limited amount of real estate.
Over the last several decades, I have collected one of the largest collection of airport directories I’m aware of, and as of 2020 my entire collection is digitized and OCR’ed. On this page, I’ll add some images from my collection showing the official documentation of these tiny runways. In this way you can see where these were actually installed.
Houston Intercontinental had two (source: 1974 Flight Handbook)
An honorable mention is reserved for a few small passenger-serving airports which ONLY had a short STOL runway. These were nicknamed STOLports.