The Kingsway Subway has been open to the public for the past few days.
...
this is I believe the first time, since the trams went, that
members of the public have been able to simply walk in off the
street, free of charge, down the slope and explore the subway ...

Most likely the first time *ever*. The general public would hardly
have been permitted to enter by walking along the tracks when it was
in service, would they?
--
Mark Brader, "It is impossible. Solution follows..."
Toronto, -- Richard Heathfield