The Underline

The Underline is a 10-mile linear park being developed in Miami-Dade County, Florida. When complete, it will run underneath the county's elevated Metrorail system from the Miami River near Brickell to the Metrorail's southern terminus at Dadeland South. The project is essentially upgrading a pre-existing bike path, known as the M-Path, into a full linear park. , the first phase of The Underline was completed in the Brickell area on February 26, 2021. The second phase, which runs from Brickell to just south of Vizcaya station, was completed on April 24, 2024. The third and final phase will be completed in 2026.

Route
The Underline begins at the Miami River in the Brickell neighborhood of Downtown Miami. At the river, it connects to the Miami River Greenway. From here, it runs south underneath the Metrorail through Brickell, Coral Gables, and Kendall, where it will end at the Dadeland South station.

At Dadeland South, The Underline is planned to connect with the proposed Ludlam Trail linear park. It will also connect with the 20.5 mi South Dade Rail Trail beyond Dadeland South, which runs along the South Dade rapid transit busway (also former Florida East Coast Railway right of way) all the way to Florida City. Together, the two paths form a continuous 31 mi off-road trail for pedestrians and cyclists. Both trails are part of the ambitious East Coast Greenway project.

Brickell Backyard
The first phase consists of the north end of the line, which is called the Brickell Backyard. The Brickell Backyard is an urban park along The Underline that includes the Typoe Sculpture Garden, a sound stage plaza, Urban Gym with basketball court, workout stations, and a running track, as well as butterfly gardens with native plants that surround gathering spaces.

Hammock Trail
The second phase consists of a linear trail between the Brickell Backyard and SW 19th Ave. This part of The Underline rehabilitates over 100,000 native plants and trees. It includes the Hammock Playground, Vizcaya Station Plaza, and the Rain Garden.

History
The Underline's predecessor, the MetroPath (M-Path), was mostly built along with the Metrorail and opened in 1984. This segment of the Metrorail was built along the former right of way of the Florida East Coast Railway's main line between Miami and Kendall, which was abandoned in 1972 and purchased by Miami-Dade County in 1979. The M-Path has been popular among cyclists, some of whom use it to commute to and from downtown, as well as runners.

In late 2011, the MetroPath was extended and a 200 ft bridge was added over the freeway style entrance to the Snapper Creek Expressway (S.R. 878) near Dadeland North station to complete the M-Path with the exception of a few small breaks at major road crossings such as near the north end at Coral Way (SW 13 Street) in Brickell and the Douglas Road area around Bird Road in Coral Gables.

In 2014, plans were made to revamp the M-Path as a linear park, taking after the popular High Line in New York City, by a group known as "Friends of the GreenLink. The University of Miami assisted in the procurement of the idea. Into 2015, led by founder Meg Daly, the proposal gained momentum and rebranded itself as [Friends of] "The Underline". Actual design work was done by James Corner, and the project was recognized by the county.