Located in Terminal 1 of Toronto’s Pearson International Airport, Tilted Spheres by American artist Richard Serra is a dominating sculpture that greets the city’s international guests. Given Serra’s taste for the supersized, it’s only fitting that the work is big enough to walk through and even to create its own echo. It’s so big in fact that it had to be installed before the terminal walls and roof could be constructed. Consisting of four huge steel fins—each one delicately curved, torqued, and coated in black rust inhibitor—Tilted Spheres (2002-04) is 39 feet long by 14 feet high.