Alexander Mitchell, the richest man in Wisconsin in the late 1800s, built the first horticultural conservatory in the state. He shared his greenhouse space with local organizations and opened his own park, Mitchell’s Grove. After his death, the city of Milwaukee bought up 30 acres of the park and established the Mitchell Park Horticultural Conservatory. The first conservatory on the site was modeled after London’s Crystal Palace. It was knocked down in 1955 to be replaced with a new design concept: three huge geodesic domes. The beehive-shaped glass domes were finally completed in 1965, 10 years after the contest was announced, with a dedication ceremony conducted by Lady Bird Johnson. The botanical garden holds over 1,000 different plant species, with each of the three domes displaying a different theme: the Tropical Dome, the Desert (Arid) Dome, and a floral Show Dome with rotating seasonal or holiday displays. The unique design of the glass orbs allows 85 percent of available light to transmit to the plants, and large fans are used to draw out heat in the summer so the domes don’t overheat. The aluminum tubing on the structures expands and contracts along with the temperature, and visitors can hear it clicking as they walk through the gardens. The Domes are a beloved icon of Milwaukee, but they are in peril. Preservation and restoration work is needed and the city is unsure of how to proceed. A task force is currently investigating options for the future, including shutting down the domes if the costs of repairs will be too high. Be sure to visit this midcentury modern marvel while you still can.