Off British Columbia's busy Sea-to-Sky Highway just north of Vancouver, is the

Mill No.3The towering structure, built from concrete and steel in 1923, sits on a mountainside slope next to Howe Sound. Britannia Mine Museum curator Laura Minta Holland says it is not only a provincial landmark, but a place steeped in history.

"It’s just so impressive when you walk in and it just prompts you to try to imagine what it would have been like when it was a working and operational mill building." Minta Holland told Â鶹´«Ã½. "I really feel it has that sense of a cathedral almost, and sometimes we refer to it as a kind of cathedral of engineering."

Laura Minta HollandMinta Holland and her team have been working for months on a special celebration to mark the mill's centennial—an exhibit chronicling its lifespan and contribution to mining in Canada is set to open in late May.

"The 20-storey building was constructed by the Britannia Mining and Smelting Company, and took 18 months, from start to finish to complete." said Minta Holland.

Historic Mill No. 3While the Britannia Mine was in use following the turn of the century, Mill No.3 only became operational after another ore processing structure burned down in 1921.

"When we say gravity concentrator, what that means is rather than moving ore up, they were always bringing ore down through the building, which was a process that took less energy and was quite cutting edge at the time."

Copper was the predominant mineral sought, but zinc, lead, silver and gold were also dug out by miners working at Mount Sheer, which was nearby. Once ore was removed, it was transported by train to the top of Mill No. 3 where it underwent it an extensive processing procedure.

Minta Holland describes the process as innovative because not only was ore "crushed by numerous giant ball mills," it was ground into a powder and run through separation machines to prepare it for shipment at a smelter for additional refining.

"The company invested in the technology of the time to make the business more profitable. It was a massive operation that employed thousands of people over the lifespan of the mill," Minta Holland said.

Miners at the Britannia MinesAlong with Mill No.3, there were two towns established by the mining company. The communities, only accessible by boat until the railway and highway were built, were where the miners, mill workers and their families lived.

"It was a wonderful place where nobody locked their doors and everyone knew one another," 85-year old Frances McKilligan told Â鶹´«Ã½ during a recent visit to the area.

Frances McKilliganMcKilligan's father, who immigrated to Canada after the First World War, worked as a foreman at the site. As for her mother, she was a cook tasked with feeding hungry, hardworking crews before and after their shift. It was a time when both the mill and mine were thriving.

"I was born steps away from Mill No. 3 in 1938, and while some people may think it rather strange to grow up there, for me, it was amazing," McKilligan said.

Despite the isolated location, the 85-year old described life outside the mill as "never dull" because there were so many amenities available.

"There was everything to do," she explained. "There was (a) gymnasium, swimming pools, badminton, tennis, theaters and so much more."

Just like the mining company invested in technology, it also invested in the two town sites. In addition to numerous recreation facilities, there were stores, schools and medical centres.

"The mining company supplied everything, people lived well and the community was very close-knit."

A miner works at the Britannia MinesMcKilligan lived near the mill until 1955, moving away only after she lost both her parents to cancer within a year of each other.

"I have so many happy memories there with my parents," she said. “I shall never, ever forget my upbringing near Mill No.3."

Over the years, 60,000 people from more than 50 different countries, worked and lived in the communities nestled next to the mill. Together, they helped transform it and the mine into one of the world's largest copper production sites.

However, the boom would not last, and after years of dwindling revenue, operations were shutdown in 1974.

"It's still standing today," said Minta Holland. "So it really is a testament to the ingenuity of the people of that time."

Mill No.3In 1987, 13 years after it closed, Mill No.3 was designated as a National Historic Site.

Since then, it has been restored and converted into an interactive museum, offering visitors a window into the world of Canada's mining history and into the lives of the people who made the site successful.

"When you come here it is a real opportunity to touch history, quite literally, by walking in and around Mill No.3, which stands here now as a massive inspiration and a true link to our rich, diverse history."