MONTREAL - Even if you've never set foot inside, you've seen its lights at night.

Built in 1962, Place Ville Marie was the first modern skyscraper in the city, and for a time the tallest building in the commonwealth.

"Place Ville Marie is the iconic building," said Nancy Dunton of Heritage Montreal's board of directors.

It is the indication of Montreal coming into its own in the 1960's -- really the move of the financial centre from what we now call old Montreal, up to the downtown core."

Over the past 50 years its owners, Ivanhoe-Cambridge, have made some changes.

"Since we've had the building we've invested over $150 million so far over the last 10 years," said Dany Gauthier, general manager at Place Ville Marie.

In September, a piece of public art will be installed at the building's outside plaza to commemorate 50 years.

A time capsule will be buried, to be opened 50 years from now.

"As a building it endures, yes, it is clearly a building built in the 60's, but it has that interesting quality of timelessness," Dunton said.

Although the 47 storeys of I.M. Pei's cruciform structure form an essential part of the Montreal's scraperscape, about half of the structure sits underground.

In 1958, the building required the digging of a massive hole in the centre of the city which would eventually be transformed into the initial seed for what has since become an expansive network of underground tunnels filled with small retail.

Place Ville Marie now sits at the centre of a network of tunnels that extend all the way to Peel and St. Catherine at one end and the city's conference centre at the other.

The building was created when New York developer William Zeckendorf signed with Royal Bank as anchor tenant, which created the financing for the construction to start.

It led a flood of movement downtown from the old banking centre on St. James St. in Old Montreal.

The Bank of Commerce nearby at Peel hustled to completion before PVM it but never quite matched its glory. The building of PVM took place during a burst of optimism and construction in Montreal that culminated with the World's Fair of 1967.

The structure was named by Mayor Jean Drapeau himself, as developers sought to duplicate the controversy of the naming of the Queen Elizabeth Hotel, a moniker which upset some Quebec nationalists.

The iconic spotlight that circles over the city at night was out of commission for about a year earlier this century following an incident when it parts of broke apart at the very moment a Dutch TV crew was filming a European version of The Amazing Race.

The building remains a bustling destination that attracts tourists, shoppers and office workers and boasts 900 parking spaces, 32 elevators and a restaurant at the top known as the Altitude 737 named after its height in feet above sea level.