This CNR roundhouse was near the present-day Queensway's Nicholas Street turnoff. Source.
This CPR roundhouse was at Nepean Bay just to the west of Lebreton Flats. Source.
The remains of this turntable built in 1871 for the St. Lawrence and Ottawa Railway were uncovered just a little to the west of the CPR one. Source.
The Canadian Northern Railway had a roundhouse at 300 West Hunt Club Road. Source.
The Canadian Atlantic Railway had a roundhouse on Elgin Street. Source.
Where you might think there would be marble on the walls and ceiling of the French Embassy's smoking room, it's birch bark. Source.
Lady Elgin in the Lord Elgin Hotel. Source.
The cornerstone of Francophone culture in Ottawa in the first half of the 20th century was the Monument National at the corner of Dalhousie and George. Here the populace gathered for classes, concerts, fiery speeches and films. But the space has been a Holiday Inn parking lot for decades now. Source.