A gleaming metal chair dangles precariously over an expressway. The ghost of a Montreal row house sticks out its staircase like a tongue. A solemn Roman temple balances on a narrow pedestal, as if riding a unicycle. Welcome to the Canadian Centre for Architecture’s sculpture garden, a constructivist circus rendered in concrete, copper, and steel.

Boxed in by access ramps and the Ville-Marie Expressway, the small park is carefully landscaped to guide visitors up its gentle slope. Its low walls trace the boundaries of long-gone farms that once occupied the site. A large concrete facade mirrors the base of Shaughnessy House, a historic mansion that is part of the CCA premises across the street.

At the top of the park, sculptures parade along the skyline as if on stilts. A mishmash of materials, shapes and styles, they’re an architect’s sketchbook brought to life—conceptual, anachronistic, and a little ludicrous. The park overlooks the formerly industrial neighborhood of Saint-Henri, and the sculptures and their plinths playfully echo the factory chimneys, grain elevators, and church spires below. One even features a building sitting in a chair, gazing out over the city.

The sculpture garden was designed by Montreal artist-architect Melvin Charney, who spent 10 years fine-tuning its transformation from a traffic island into a park. It opened in 1990. Charney called his creations “allegorical columns,” and saw them as a synthesis of architecture, landscape, and sculpture. “The chairs in the garden are set in the sky,” he wrote, “for the comfort of the imagination.” With names such as “The Obelisk-Chimney” and “The Temple-Silo,” they reference the ever-changing cityscape and architectural legacy of Montreal.