Dear Urban Decoder: What was the original intent for the large, unfinished, grey concrete structure that sits above the underground parking lot just west of Yonge Street between Adelaide and Temperance?—Eric Brazier, Yonge and Eglinton

Back in 1990, the Bay-Adelaide Centre was slated to be Toronto’s next big skyscraper, a sleek 57-storey edifice just a few metres shy of First Canadian Place in height. Ground was broken, and the tower’s guts—a vast 1,100-car underground parking garage and a seven-storey elevator core—were built. But then the recession of the early ’90s buried the downtown real estate market, and the project stalled. Current co-owner Brookfield Properties Group still plans to complete the development but is waiting until a big tenant comes on board. Though design details are up in the air, the current plan is for a mix of offices and—big surprise—condos.