In 2021, Ken Griffin gave $5 million to Miami’s Underline; 5 years later, the 10-mile urban park is approaching its final phase

Ken Griffin is billionaire investor and the founder of Citadel. He donated $5 million to Miami's Underline in December 2021. The Miami Herald reported the gift as part of his philanthropic contributions to South Florida.

What is the underline?

The Underline is a 10-mile linear park and urban trail running beneath Miami's elevated Metrorail line, from Brickell to Dadeland South. It passes through 14 neighbourhoods and eight Metrorail stations.

The project was developed as the land beneath the elevated railway had been left with rubble and debris after the rail infrastructure was built in the 1980s. It was made to turn this space into a public space, and provide spaces for walking, cycling, recreation and community activities.


The development was in three phases. The first half-mile section, Brickell Backyard, opened in 2021. The second phase opened in 2024, adding 2.25 miles of trail and a public playground. The third and final phase was scheduled to open by the end of 2026.

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The final phase will reportedly include 12 public spaces and amenities. It will include an open-air-market and cultural hub, a dog park, fitness facilities, and pickleball and basketball court near the University of Miami.

How was the project funded?

It had received public funding from Miami-Dade County, the state of Florida, local municipalities and a US Department of Transportation grant. It also included private donations. Friends of The Underline had raised more than $25.7 million in private donations by July 2026 and projected that the total would approach $30 million by year-end.

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Griffin's donation was with the aim of establishing an endowment for the park's long-term maintenance. The nonprofit has an annual operating budget of approximately $10 million. It covers maintenance, community events, programming and workforce development. The project therefore required continued financial support beyond the construction phase.