NEW CANAAN — Philip Johnson saw something in the dramatic landscape of the Rippowam River Valley in the 1940s. On nearly 50 acres of sloping hills and dense forest off of Ponus Ridge Road, in a town not yet known as a hub of Modernist homes, the architect would build his now iconic Glass House.

“The Glass House is all about the site,” said Irene Shum, curator and collections manager at the Glass House, which was built in 1949. “Before he found that location he had started designing his home, but it was a concept. It wasn’t until he found the promontory on which the house sits that he decided this was the place.”

The structure is now the focal point of a rich architectural heritage in New Canaan, including homes built by Johnson’s contemporaries — John Johansen, Marcel Breuer, Landis Gores and Eliot Noyes, collectively known as the Harvard Five — and is one of five homes designed by Johnson that will be featured in “Philip Johnson’s New Canaan,” a unique tour sponsored by the Glass House on Oct. 22 from 1 to 7 p.m.

The tour is a celebration both of Johnson’s 110th birthday and the Glass House’s 10th year open to the public. It will include visits to the Hodgson House (1951), the Alice Ball House (1953), the Wiley Speculative House (1954) and the Boissonnas House (1956), all of which, with the exception of Wiley, Johnson was commissioned to build.

According to Shum and Laura Pla, an educator at the Glass House and an organizer of the tour, New Canaan in the mid-20th century was a very different place.

“There were a couple of things happening in New Canaan in the 1940s that attracted these architects: easy access to New York City via the Metro North or the recently completed Merritt Parkway, a really nice downtown area not bisected by Route 1 or I-95, a building department excited about these young architects arriving here and experimenting, and plenty of inexpensive land available,” Pla explained.

For Johnson and the Harvard Five, New Canaan represented artistic and architectural opportunity. It would become the setting for what was an intensely creative period in American architecture.

“I think New Canaan was a place for Philip Johnson to experiment with materials and design ideas. It was his architectural campus, his lab,” Pla said.

According to Shum, the homes in the tour, though built within less than a decade of each other, show Johnson at different creative periods.

“For the most part you see the early houses that are directly influenced by the Glass House. But there’s a transition point where Johnson used more historical references and what you see is the influence of van der Rohe,” Shum said, referring to the pioneering Modernist architect, Ludwig Mies van der Rohe, with whom Johnson collaborated and had a close personal friendship.

Johnson’s urban designs were celebrated last spring in “Philip Johnson’s New York,” a tour of the architect’s work in Manhattan.

“Obviously, Johnson’s New Canaan architecture is more residential, whereas the New York tour featured more of his commercial designs and high rises. Paired together you see the full scope of work,” Shum said.

Interestingly, the New Canaan experiments of Johnson and the Harvard Five were not universally accepted at the time, according to Pla.

“This was an unusual architecture. Mid-century modern was new to the community and a lot of locals at the time didn’t understand what the architects were doing. They were asking ‘What are these Kleenex boxes?’” she said.

But in time, the designs of the Harvard Five, and Johnson in particular, have come to be revered.

“New Canaan is one of those communities, like Palm Springs, where you have a rich heritage of mid-century modern design that you wouldn’t necessarily suspect in a Fairfield County suburb. It’s special,” Shum said.

justin.papp@scni.com; @justinjpapp1