6.7K 
Above the soon-to-open Eglinton Line 5 Don Valley station on Eglinton Avenue East at Don Mills Road, preliminary work has begun on an elevated subway station as construction on Ontario Line 3 progresses city-wide. This future interchange station will serve as the initial northern terminus of what will be Toronto's first ever wholly automated rapid transit line, connecting riders to destinations in East York, The Port Lands and Downtown. Previously slated to be named Science Centre station due to the proximity of the Ontario Science Centre to the interchange, that facility’s controversial closure in 2024 required a renaming of the station, now reflecting its setting within the expansive lands surrounded by the Don Valley.
Any trip on transit into Downtown from the area currently requires multiple modes of transit, each involving a bus slogging through traffic, with riders being delivered to the core only after about an hour. With the opening of Ontario Line 3, currently estimated for the early 2030s, Metrolinx has stated that the same trip will take less than 30 minutes, all in the comfort of a single-seat subway ride. Before that, of course, east–west travel along Eglinton Avenue will become significantly faster and more convenient with the opening of Eglinton Line 5. According to Metrolinx, commutes to the office cluster at Yonge and Eglinton or to the employment hub along the “Golden Mile” in Scarborough are expected to be up to 60% quicker.
This soon to come revolution in connectivity is bringing a wave of development area, set to permanently reshape the hemmed-in neighbourhood and tie it better into the urban fold. To the south of Eglinton Avenue, in the 'Tower-in-the-Park' neighbourhood of Flemingdon Park, high rise projects and proposals have sprung up with increasing frequency, some reaching as high as 60 storeys. While a great deal of these proposals seek to build on the underused lawns, offices, and parking lots of the area, a number seek to raze aging low-rise apartments and slab towers, prompting fears of displacement in the long disadvantaged neighbourhood.
To the north of Eglinton, where industry and offices were once predominant, gargantuan mixed-use redevelopments are currently underway, the most notable of which is the Crosstown Community. Located on the former site of IBM's head office and Celestica manufacturing facility in Toronto, the 60-acre development is one of the largest residential projects in Canada. Towers up to 44 storeys high are planned along the site’s frontages on Don Mills Road and Eglinton Avenue, with rows of townhouses and mid-rises set to occupy the interior of the site. While several phases are underway, at full buildout — a milestone still years away — the development will contain 4,921 new homes, creating an entirely new neighbourhood in the heart of Toronto. Many more units are planned on neighbouring sites.
The rapid urbanization of the area will mark the second major transformation of the Don Valley’s southern flats in less than a century. Geographically isolated between the east and west branches of the Don River, the lands now known as Flemingdon Park and Wynford–Concord remained largely undeveloped throughout the first half of the 20th century. While other districts equally distant from the Old City, such as New Toronto, The Beaches, and Forest Hill experienced explosive growth during the 1920s, 1930s, and 1940s, industry and residential subdivisions failed to take root between the branches of the Don during those same decades of expansion.
The area's bucolic status quo would be fractured by the massive roadway and infrastructure build out Metro Toronto undertook following the conclusion of World War 2. Eglinton Avenue was extended east from Leaside into Scarborough throughout the 1950's, diving down into the river valley before bridging the Don itself on a 100m long viaduct. Simultaneously, work for the Don Valley Expressway was progressing, with the highway reaching Eglinton Avenue by 1961, putting the long undeveloped lands between the branches within a 20 minute drive of Downtown.
Seeking to decentralize the city and prevent the suburbs from stagnating as bedroom communities, major cultural and civic centres were constructed across the rapidly developing boroughs. One of the most acclaimed was the Ontario Science Centre, which opened in 1969 at the southwest corner of Don Mills and Eglinton. A brutalist architectural gem set atop the forested banks of the Don Valley, the Science Centre quickly became a beloved destination for Ontarians of all ages.
Time, and more importantly under-funding, was not kind to the iconic building, however, and difficulties with aging exhibits and declining visitor counts trailed the museum some decades after its opening. Despite this, plans for relocation of the institution were long thought unserious until Ontario Premier Doug Ford's announcement of plans to relocate the facility to the former Ontario Place grounds on April 18th, 2023. This unexpected announcement sparked a flurry of backlash from civic and professional organisations, in addition to a large public outcry.
Despite broad and continued opposition to relocation plans for the Ontario Science Centre, the Province, which holds final authority over the move, showed little interest in alternative plans that would seek to renew and maintain the existing building. As a result, the building has sat vacant since its abrupt closure on July 21, 2024. The complex's future remains uncertain.
With the closure of the Ontario Science Centre, the name of the transit station planned for the intersection of Eglinton Avenue East and Don Mills Road had become an anachronism. To address this, a formal name change was announced in March 2025, that it would now be known as Don Valley station. Adoption of the new name on government imagery has been slow: nearly six months after the announcement, Infrastructure Ontario’s page for Ontario Line 3 still displays the outdated map identifying the stop as Science Centre station, as shown below.
Regardless of the naming difficulties, progress on the station and on Ontario Line 3 more broadly has continued across the city. Construction has resumed at the intersection of Don Mills and Eglinton, following a brief pause in 2023 and 2024 after years of work there for Eglinton Line 5. The formerly grassy lawn at the northeast corner of the intersection has been taken over for staging, in preparation for the construction of an elevated concrete guideway that will carry Ontario Line trains above the wide, traffic-laden streets below. While work on the guideway itself is still some time away, the need to integrate with the existing below-grade Eglinton Line 5 station will ensure sustained construction activity at the site for the foreseeable future.
UrbanToronto will continue to follow progress on this development, but in the meantime, you can learn more about it from our Database file, linked below. If you'd like, you can join in on the conversation in the associated Project Forum thread or leave a comment in the space provided on this page.
* * *
UrbanToronto has a research service, UTPro, that provides comprehensive data on development projects in the Greater Golden Horseshoe — from proposal through to completion. We also offer Instant Reports, downloadable snapshots based on location, and a daily subscription newsletter, New Development Insider, that tracks projects from initial application.
| Related Companies: | Arcadis |
