National Historic Landmarks are typically associated with our country’s history—sites like the infamous island Alcatraz or Manzanar, one of the camps where Japanese-Americans were imprisoned during World War II. But in Southwest Fresno, one landmark owes its historic status to trash. It’s a landfill—at least, it used to be. In this interview, we speak to an environmental historian about the gritty past of what is now a city park. Listen to the audio for more on where it is, what it looks like now, and why the former Fresno Sanitary Landfill was innovative enough to be named a National Historic Landmark.