Located at the intersection of Wells and McKinley Drives within the 1,293-acre Forest Park, this Art Deco greenhouse was designed by engineer William Becker and completed in 1936 with assistance from the Public Works Administration. Public floral conservatories gained popularity in the city in the 1910s, when pollution and smog threatened much of the city’s flora. City gardener John Moritz was tasked with exhibiting pollution-resistant plants in greenhouse displays for public enjoyment. The first such greenhouse, nicknamed the Jewel Box, proved wildly popular and inspired more elaborate seasonal exhibits throughout the 1920s. In 1933, Mayor Bernard Dickmann allocated $75,000 to erect a larger, permanent greenhouse. Becker, then St. Louis' chief engineer, studied climate patterns to produce a design measuring 144 feet long and 55 feet wide, with more than 4,000 glass wall panes set into wood and iron supports, and five stepped levels of wood roofing with glass clerestories. The design also includes three reflecting pools south of the structure, along with a network of footpaths connecting the greenhouse to the park’s existing pedestrian routes. Inside, the space accommodates rotating floral exhibits. The structure, officially designated as the Jewel Box, opened in 1936. Seasonal displays (e.g. chrysanthemums, lilies, azalea) continue to attract visitors.
Following city budget cuts in the 1990s, local volunteer groups formed partnerships with the city department of parks and recreation to maintain the landscape setting surrounding the Jewel Box, including the lily ponds within the reflecting pools and beds lining the pedestrian paths. A $3.5 million renovation of the structure was completed in 2002, with SWT Design landscape architects. The Jewel Box was listed in the National Register of Historic Places in 2000.