For some, the prospect of visiting a World Expo is an opportunity that cannot be missed. When Expo 1967 took place in Montreal, Tony Whittemore and his brother Jeff, aged only 11 and 9, were desperate to discover the Expo’s magic. The only problem – they lived 350 miles away, in Needham, Massachusetts.

It was on 28 April 1967 – 55 years ago today – that Montreal invited the whole world to discover “Man and his World” at Expo 1967. The spectacular World Expo, which marked Canada’s Centennial, gathered 60 countries and registered over 50 million visits during its six-month run. Here are five interesting facts about Expo 1967 Montreal:

Israeli-Canadian architect, urban planner and author Moshe Safdie is in the spotlight for this week’s instalment of the A to Z of Expo Architects for designing the Habitat 67 urban residential complex for World Expo 1967 Montreal.

Engineer, architect and pioneer of tensile structures, Frei Otto takes the “O” spot for this week’s A to Z of Expo Architects. Rising to fame for designing the Federal Republic of Germany’s revolutionary pavilion at World Expo 1967 Montreal, Otto later added to his Expo contribution by co-designing Japan’s iconic paper pavilion at World Expo 2000 Hannover.

Following on from Gustave Eiffel, the A to Z of Expo Architects moves on to another groundbreaking designer who made waves for his original and bold creations: Richard Buckminster Fuller.

Perhaps as celebrated for his unbuilt projects as for the structures that saw the light of day, one of Fuller’s most iconic creations is World Expo 1967 Montreal’s United States’ pavilion, the largest geodesic dome at the time of more than half a sphere, today known as the Biosphere.

Expos are blank canvasses for innovative structures and architectural concepts, giving new and established architects the opportunity to design memorable pavilions. One such architect is Karl Schwanzer, the celebrated Austrian architect who was born 100 years ago today.

A major figure in post-War architecture, Karl Schwanzer first made the headlines for his native country’s national pavilion at Expo 1958 in Brussels. This success was followed nine years later when he designed not only Austria’s pavilion at Expo 1967 Montreal, but also the Expo’s on-site Vienna Kindergarten.

Today marks the 50th anniversary of the French national day at Expo 1967 Montreal, a World Expo with the theme “Terre des Hommes” (Man and His World) which focused on mankind’s progress and innovations.

The theme of the French pavilion was “Tradition and Invention”. Among the exhibitions that were showcased were a model of the bathysphere “Archimede”, a colour television manufactured in France, and objects from Jacques-Yves Cousteau’s marine expeditions.

Passports give us the opportunity to cross borders and discover new horizons, while keeping a record of our journeys throughout the world. As the first day of the "Week at Expo 2017" series, we celebrate the 50th anniversary of Expo passports and their continued popularity to this day.

Organisers of Expo 1967 Montreal first issued Expo passports as a novel form of ticket, with a separate page for each participating country to encourage visits to as many pavilions as possible. Visitors could either purchase an adult passport, or a youth passport. Shaped like a small booklet, these “passports” were sold at the entrance to the Expo site, and have since become one of the most popular souvenirs for visitors who want to keep track of all the different pavilions they visit.

On 28 April 1967, the gates to Expo 1967 Montreal opened to the public, marking the start of a new and modern era for the city. The Expo, which celebrated 100 years of Canadian Confederation and 325 years since Montreal’s founding, was a major accomplishment for the city and for Canada.

During the six months that the Expo was open, 50 million people passed through the turnstyles, eager to discover the latest innovations and explore different interpretations of the theme “Man and His World” (in French: Terre des hommes).

Among Montreal’s many celebrations this year, the 50th anniversary of Expo 1967 is undoubtedly the one that brings on the strongest feelings of nostalgia among its residents. In the same year as it marks the 375th anniversary of the city’s founding and 150 years of Canadian Confederation, the city of Montreal is organising a range of activities to remember the glorious six months of 1967 when the city welcomed the world under the theme “Man and his World.”

On 4 March, Montrealers will be able to rediscover the excitement and wonder of Expo 1967 when the city holds its annual Nuit Blanche late night cultural event.