The Ohio and Ontario Street corridor in River North holds a concentration of design showrooms, furniture stores, and interior design businesses that serves Chicago's interior design industry — a sector of the economy that is concentrated in the neighbourhood given its proximity to the Merchandise Mart, the world's largest commercial building and wholesale design center, across the river.
The Merchandise Mart (now TheMART) is partially open to the public for its restaurant and retail tenants; the design showrooms on upper floors require trade credentials. The building itself — a 1930 neoclassical structure of extraordinary scale (25 floors, 4 million square feet) — is worth seeing for its presence on the riverbank. Kinzie at the river.