File:Casa Loma Stables, Toronto, Ontario (29889771562).jpg

The northern part of the Casa Loma Estate, comprising the Hunting Lodge, Potting Shed, Greenhouses and the Stables complex was begun in 1905 by builder Herbert Elgie, according to the design of the prominent Toronto architect E.J. Lennox. Sir Henry Pellatt, one of Edwardian Canada's wealthiest men, was a prominent industrialist, financier and military officer of the Queen's Own Rifles Regiment. He took up residence in the Hunting Lodge with his wife Mary in 1906, and watched as their permanent home, Casa Loma, was constructed across the street between 1911-1913.

The Stables complex was the first building erected on the estate, and accommodated Pellatt's Thoroughbreds, Hackneys, Clydesdales and Percherons, as well as his much loved 'chargers' Prince and The Widow. An impressive structure, the Stables features red brick construction, cast stone trim and a Mannerist-inspired design that owes much to the stables of large European houses.

Situated around a central courtyard, the two elaborate entrance blocks are the main features of the L-shaped complex. The northerly doorway opens into the Stables, while the westerly doorway opens into the Garage. Both entrances feature heavily blocked engaged columns that support heraldic beasts and the Pellatt crest. Other notable elements include a stone squirrel (representing industry) and the QOR Regimental insignia on the Stables tower.

The Stables served not only as accommodation for horses and carriages but provided small apartments for the stable hands and groomsmen on the upper floors. Beneath the stables were rooms for propagating mushrooms, asparagus and rhubarb. The interior of the ground level of the Stables features a carriage room with wooden trusses, walls clad in the regimental colours of the Queen's Own Rifles, mahogany stalls and Spanish tile flooring.

The stalls still bear the names of Pellet's much loved horses- Casa Loma Belle, Prince Highgate (Prince), Matchless (of Londesborough), Lord Kitchener, The Widow and Indian Chief. Some of these horses were carriage horses, and others saddle horses, but almost all had won numerous coveted prizes and championships throughout North America. The ribbons that they had won covered one wall of the Stables, and the trophies collected filled a room.

Matchless and Lord Kitchener were registered Hackney Horses and the latter had never been beaten in the show ring. Indian Chief, grandson of the famous American racehorse Hanover, was a young chestnut Thoroughbred who was schooled in dressage by Pellatt's stable manager, Thomas Cushing. The Widow was the only Canadian bred horse in the stables and was a much-loved mount, accompanying Pellatt twice to Britain for military maneuvers.

When Pellett moved out of Casa Loma for the last time in 1923, his horses moved with him to the fine accommodations of Mary Lake. Mary Lake was Pellatt's country estate where he raised prize-winning cattle, sheep, horses and fowl, and was situated in King Township, a half an hour north of Toronto.

In 1936, The Kiwanis Club of West Toronto (later known as the Kiwanis Club of Casa Loma) entered into a lease agreement with the City of Toronto, who had acquired the estate from Pellatt for non-payment of property taxes. In 1937, the property was opened to the public as a heritage attraction. Who would have imagined that a short time later the Stables would serve as a top secret location for the assembly of a newly developed technology.

ASDIC, named for its inventors, stands for Anti-Submarine Detection Investigation Committee. It was an early form of sonar and could detect a U-boat at a distance of 8 km. This device enabled Allied naval vessels to search for and destroy enemy submarines. As the original production site for ASDIC had been bombed in London, a new assembly location was found in 1941 in the Casa Loma Stables. Little did the touring public realize that behind a small padlock and a sign which read "Construction in progress-sorry for the inconvenience" ASDIC was being secretly assembled.