Chorley Park
Built: 1915 (started in 1911)
Demolished: 1961
What exists there now: Parkland
Why it's missed: Chorley Park was the fourth and last official residence of the Lieutenant Governor of Upper Canada. Architect F.R. Heakes modelled it after the chateaux of the Loire Valley. The opulent building closed in 1937 due to the high maintenance costs. It served a few other uses before being razed.
Board of Trade Building
Built: 1892
Demolished: 1958
What exists there now: EDS Building
Why it's missed: Designed by New York's James &
James firm, the Board of Trade held a prominent place on the northeast
corner of Yonge and Front streets. The rounded building was the perfect
companion to the Flatiron a couple of streets away.
Grand Opera House
Built: 1874 Demolished: 1927 What exists there now: Scotia Plaza Why it's missed: A fabulous Second Empire-style building with an an intriguing history courtesy of one-time owner Ambrose Small, the millionaire that one day up and vanished, nothing like it remains in Toronto.
Old Union Station
View of Union Station from waterfront
Built: 1873
Demolished: 1931What exists there now: Citigroup Place
Why it's missed: As wonderful as the current Union Station is, think of what it'd be like to have the previous iteration of the station preserved and used for another purpose.
The Crystal Palace, 1879-1906
After attending a preview of the first CNE, a reporter for the Globe newspaper stated that: The ground floor of the Crystal Palace will be devoted to musical instruments, gas fittings, saddlery, hardware, chinaware, billiard tables, etc.
Toronto General Post Office
Demolished: 1958
What exists there now: State Street Financial Centre
Why it's missed: This was Toronto's 8th post office and acted as the summit of the gorgeous Toronto St. Designed by Henry Langley, it was one of the city's most ornate Second Empire buildings.
Trinity College Campus
Trinity College 1929
In 1912, the City of Toronto purchased the
32-acre site where Trinity College was located. In 1925, Trinity College
relocated to the campus of the University of Toronto. Some of the
buildings on the former site were renovated to accommodate other
purposes, but the structures suffered from lack of proper maintenance.
In 1929, a fire caused extensive damage to them. However, the buildings
survived until 1956, when they were all demolished except for St.
Hilda’s College. It became a community centre and survives to this day. 
The site of the demolished buildings of Trinity College is today named Trinity Bellwoods Park. The most visible reminder of the former campus of Trinity College is the impressive gateway on Queen Street, erected in 1905-1906, designed by Frank Darling. In the modern era, they provide the main entrance to the spacious park.
Hanlan Hotel, located on the Toronto Islands, Lake Ontario, Canada
This 1889 map depicts Hanlan’s Point and the hotel on the northern tip of the small eastern peninsula. Map by R. L. Polk and Company, Toronto Archives. Landfill joined these two small peninsulas into one land mass and the area to the north of Hanlan’s Hotel was eve eventually filled in, and is where the airport on the Island is located today.
Armoury
| 1891 | 1963 | University Avenue and Armoury Street |
The above photo of the armouries is from the Toronto Archives, Fonds 124, Fl0001, Id 0064. The view is of its west facade, on University Avenue.
Sketch of the Toronto Armouries dated 1893, from the collection of the Toronto Public Library, r-5511.
Toronto’s armoury was to be located on the
east side of University Avenue, a short distance north of Queen Street
West, and south of today’s Armoury Street. Thomas Fuller chose the solid
Romanesque Revival style of architecture as it was suitably
militaristic in appearance, similar to the great fortresses of ancient
times. 
Built in 1891, the Toronto Armouries officially opened on May 17, 1894 according to the official story but we have a picture from 1893. In the interior of the armouries was a great drill hall measuring 280’ by 125’, with a ceiling that soared 72’ above the floor.
