The Underline is transforming the land below Miami’s Metrorail into a 10‑mile linear park, urban trail, and public art destination. Friends of The Underline (FUL) is a 501(c)(3) nonprofit with a culture steeped in entrepreneurship and innovation and committed to the mission of transforming safety and mobility and improving public health, environment, and community by building and programming The Underline as an extraordinary public space in Miami’s urban core.