I had the privilege of touring Toronto's R.C. Harris Water Filtration Plant during Doors Open. It is an Art Deco gem, and a wonderful celebration of infrastructure with marble and brass details and a beautifully sited perch on the edge of the lake. I love that a colony of swallows has made nests at the apex of every brick relief; at first glance one assumes that the nests are part of the original architecture. Instead they contribute a surprising living detail, each inhabited by a family of the graceful birds. It is lovely to visit such a poetic, well preserved and still-functioning reminder of Toronto's history. One wishes that there were not so few examples to admire.