Cities all over the world experience physical and cultural changes through growth. Few are as intimidating for an architect to work in as Jerusalem.

Founded in 3000 B.C., the holy city ushered in an era of new development after World War II. A growing population, tourism, and politics, all laid the groundwork for a construction boom with mixed results. The city asked Moshe Safdie, a Haifa-born architect based in Montreal at the time, to design and build on a prominent 28-acre site around the Wailing Wall without taking away from its history.

In The Innocent Door, a 1973 documentary by the National Film Board of Canada, the debate over what modern Jerusalem should be is hashed out among colorful locals in-between philosophical musings by Safdie.

The then-35-year-old architect set out to discover what about the old city’s neighborhoods worked and could be replicated in a modern world. New construction, he says in the documentary, can be in harmony with the old “if it generates from the same value system.”

In the documentary, Safdie points out a series of mundane and thoughtless modern apartment towers that show exactly what locals are afraid will ruin Jerusalem’s character. One city councillor even goes as far as to say regarding new housing, “The moment that a Jerusalemite [identifies] his own house by a street name and the number of his own home then the human element will be lost.”

Safdie praises a residential village nearby filled with visual variety, a mix of public and private spaces, and its seamless integration into the site’s topography as what architects should be building. With only a recently finished rabbinical college to show at the time, Safdie points to models of what else he planned to build nearby, architecture that is in harmony with the past and encompasses the “innocent doorways” seen in Jerusalem. Such a feature, he explains, lead from walled streets to pleasant courtyards. “You’ve got the trees sticking above the walls, you have the suggestion of something but you don’t realize it until you go through that you’re in another world,” Safdie says of the innocent doorways. “They’re kind of enclaves.”

Today, under Safdie’s plan, there are hundreds residential units, multiple hotels, a commercial corridor, and a bus terminal. With buried parking and homes that look over pedestrian areas, the architect has left a meaningful-yet-subtle mark on the old city. Just as he intended.