At the entrance to the garden, the area closest to the busy roadway intersection, Jensen placed a monumental garden shelter, known as Flower Hall, and a formal reflecting pool. The designer of the structure is unknown, however, it was possibly Jensen himself, or his friend, prairie school architect Hugh Garden. East of the building, the garden becomes more naturalistic. Jensen included perennial beds, a lily pool, and unique prairie-style benches. In 1928, the West Park Commission constructed a fieldhouse in Douglas Park. The structure was designed by architects Michaelsen and Rognstad, who were also responsible for other notable buildings including the Garfield Park Gold Dome Building, the Humboldt and LaFolette Park Fieldhouses, and the On Leong Merchants Association Building in Chinatown. In 1934, Douglas Park became part of the Chicago Park District, when the city's 22 independent park commissions merged into a single citywide agency.