Keystone Island 1988
Keystone Island is a roughly circular construction of natural cleft and carved Florida fossilized limestone - called Keystone. It is 45 feet in diameter, rising to a height of 12 feet. The site-specific project was commissioned to accompany the new Dade County Courthouse, designed by Arquitectonica. As the building itself is such a strong presence, Zimmerman elected to place her work away from the courthouse and in the lagoon behind the building. Her work links the architecture to the environment; it is an integral aspect of the overall scheme.
A concrete walkway, cantilevered over the lagoon, leads visitors to the island. This walkway was initially part of the Arquitectonica design and Zimmerman incorporated this axis into her own plan. It now looks as if the island was a pre-existing island in the water and that the pier was built to meet it.
The island is dominated by the irregular profile of the oolitic limestone that forms its crown and divides the circle into discrete sections. This material was selected because it is native to the area. Imbedded in its heavily textured surface are clearly visible and identifiable marine fossils such as clams and corals. In addition, Zimmerman noted that panels of this stone were used frequently as decorative elements in Miami’s buildings of the 1920's.
Cut limestone steps lead down to the water’s edge; they look as if they had been carved into the natural cleft stone, but, in fact, they are placed over a concrete foundation. There is seating at the top and bottom of the island. On the lower level a visitor can face a small “tidal pool” of calm water, backed by a wall of the organic stone formation, or look out toward a mangrove forest - the last remnant of the forest that edged most of Biscayne Bay.
The project, dominated by the irregular organic form of the limestone mound, looks as if it always belonged to its site, in contrast to the colorful, high-tech, Arquitectonica building, which is faced with polished surfaces of glass and marble. At the same time, however, the circular form of the island echoes the curvaceous design of the architecture. Zimmerman’s design humanizes the imposing courthouse environment and links it to the natural surroundings.
Dade County Courthouse, North Miami, FL
Oolithic limestone, concrete, and tidal water
Metropolitan Dade County Art in Public Places