When William Lyon Mackenzie King became Canada’s tenth prime minister in 1921, he refused to move out of the Parliament Hill office he occupied as the Opposition leader.

Decades later, it’s easy to see why. Mackenzie King’s office was decorated with a beautiful fresco that remained hidden until restoration crews peeled back the walls in the spacious room where NDP Leader Thomas Mulcair now spends his days.

The mural was painted by an Italian artist and feature images of a fallen knight in battle, including one scene of an angel hovering above. It’s believed that the angel was modelled after Mackenzie King’s mother.

“Some of the paintings you can see have been gone over so many times you’ve almost lost the detail,” Mulcair said as he gave CTV News a tour of his office.

The fresco is yet another historic discovery in an office full of quirks. Mackenzie King also had a secret door installed that connects to another room so that he could escape from unwanted visitors.

“The office itself has a glow, thanks to all the woodwork and the panelling around it. And yeah, you can sense a lot of history in here,” Mulcair said.

With a report from CTV’s Richard Madan