On May 2, Russia’s preeminent Mariinsky Theatre will celebrate the grand opening of a new, 851,575 square foot addition on a neighboring site, just west of the company’s original 1860 theatre and 2006 concert hall, in the heart St. Petersburg. Designed by Toronto-based Diamond Schmitt Architects, Mariinsky II will be one of the largest theatre and concert venues in the world, providing a 2000-seat auditorium, state-of-the-art production facilities, and naturally lit rehearsal rooms, along with a rooftop amphitheatre and terrace.