Calling a building a landmark is a lot different than appraising its quality; a landmark can be either lovely or appalling, but its importance is difficult to dispute. It was either built or evolved to fulfill a function, defining some essential aspect of the city, providing geographical guidance, or evoking some crucial stage in the city's history.

The 10 entries below are, to my mind, crucial to the Toronto we know and love, and would measurably diminish the city if they were to vanish somehow.

Here's my list of the top landmarks in Toronto.

See also: The top 10 landmarks in Toronto (Take 2)

CN Tower
You could try to be coy and demote it lower on this list, or pretend to be cool and ignore it altogether, but the fact remains that this freestanding relic of pre-digital telecommunications is the gargantuan souvenir pen than anchors Toronto to the Lake Ontario shoreline like a straight pin through a butterfly.

You can be an engaged, proud, fully-fledged citizen and never ascend to its observation deck, but chances are if you've lived or worked downtown you've used it to orient yourself, or shrugged and sent visiting friends or relatives there as part of their sight-seeing itinerary.

Even before it provided the title to a pretty good punk rock song, its name had become a self-contained entity, and by now there's at least a generation that's grown up in its shadow that probably can't tell you what the "CN" stands for.

For those of us with memories of its epic construction, there's something jarring about getting an up-close view of the patchwork stains on its concrete and our memories of it when it was new, gleaming with the dull white glow of a slightly qualified future.

The Gardiner Expressway
Architect Graeme Stewart, author of Concrete Toronto: A Guide to Concrete Architecture From The Fifties To The Seventies, calls it "a heroic mid-century construction that defines the experience of entry into Toronto - the platform for the most spectacular views."

With time, it's become obvious that a curtain of condos have done more to cut us off from our lakeshore than the Gardiner's forest of columns, and that reclaiming the DMZ under the roadway is potentially more creative and rewarding than tearing it down. Reconnecting the western beaches where the Gardiner runs at ground level, however, will be a much bigger challenge.

Robarts Library
They called it "brutalism" for a reason, but this U of T landmark has weathered far better than most other examples of this '70s architectural genre. Shawn Micallef, Spacing co-founder, Toronto Star columnist and author of Stroll: Psychogeographic Walking Tours of Toronto, is forthright in his affection for "Fort Book."

"I genuinely love this building," Micallef writes, "and not because I get a kick out of the near-violent reactions some people have to it. It's everything you want in a library: solid, safe, lots of passages and nooks to hide in and read."

"Separation from the outside is also important - almost like going on a book vacation, where the troubles of regular life are left on the sidewalk. On all the floors there are surprising windows looking out over Toronto from various angles, and equally surprising atriums on the higher floors. I'm not sure what the haters are angry about as the details are done right too: smooth wood and sculptural concrete."

"If this was nature, it would be a world-wonder and we'd all want to hike there, but since people made it, somehow it's bad. One of the best libraries I've been in. Perhaps outside could use some more activity and animation, but a library is not a store, arcade or tavern - the approach of a building like this is as important. I wonder if those haters aren't just a tad over sensitive to things."

Micallef's enthusiasm had me re-examining my own feelings for Robarts, but it was while walking around it with my camera that I was forced to admit that, in at least one way, it has something essential to great architecture - no matter where you point your lens, you can't take a bad picture of the damn thing.

The Bloor Viaduct
It isn't the only bridge over the Don River, but it's the most iconic - the physical symbol of the connection between the city's eastern and western halves, which are divided by the Don more firmly than Yonge Street. If you believe that Toronto has a split personality parsed neatly on either side of that river - and I do - then you know how crossing this bridge is a palpable journey from one to the other.

Besides being a setting for one of the most famous and unreadable novels about the city, it's also a fantastic symbol for the city's past and present. Finished in the final months of WW1, it was built with a lower deck meant to accommodate the subway that wouldn't cross it until 1966 - foresight and ambition that seems to have been lost today. With the completion of the suicide-thwarting "Luminous Veil," the bridge became a symbol of a more anxious city, willing to sacrifice unimpeded views in the name of diminished risk.

Knox College (1 Spadina Crescent)
There's another building on the U of T campus with this name, but the original sits athwart Spadina north of College in all its slightly decrepit Victorian haunted house glory. Queen's Park and Old City Hall do the same thing to University Avenue and Bay Street, but Graeme Stewart calls it "one of best examples of the tradition in Toronto where a major institution terminates the north end of an avenue. Spadina's Knox College is the most vibrant and urban of these terminating vistas."

Since the Presbyterian Church moved to newer digs, it's been a veteran's hospital where Amelia Earhart was a nurse, a medical research lab, and the site of an unsolved murder and a recent ghost-hunting death. For years it was inaccessible to pedestrians unless you made an illegal crossing, one eye watching for a streetcar hurtling around the shoreline of this Gothic revival island.

TTC signs
In the opinion of self-styled "meta-preservationist urban gadfly" Adam Sobolak, a landmark doesn't need to be a building, so he nominates the TTC's distinctive "ribbon and shield" logo: "Other than London Transport, I don't know of any other major comprehensive municipal transportation network that is so defined by its unique symbolic identity; and one which in its turn so indelibly defines one's experience of the city."

"While not as self-consciously 'modern' as other identities (London's pioneering efforts not excluded), it also transcends any inherent and equally self-conscious 'retro' qualities - as such, it may be the timeless ultimate in transit identities, anywhere.

Wherever you go, encountering a TTC logo (on a t-shirt or wherever) point-blank exclaims, 'Toronto' - and more viscerally than your usual postcard New City Halls or CN Towers." Given the TTC's much-diminished reputation, it seems like its visual branding is the one thing it hasn't screwed up, though it's tempting to imagine how much it could be improved by contracting out its souvenir business to, say, Red Canoe.

Maple Leaf Gardens
Even in the long intermission to its post-Leafs glory days, Shawn Micallef considers the Carlton St. hockey palace a cultural and civic monument. "Admittedly being an arena, it didn't do much for the sidewalks surrounding it (though that's being changed with its new uses), but we had an arena right in the middle of a residential and commercial neighbourhood, and it worked just fine for decades."

"It's subtle Art Deco flourishes are quite lovely and I hope they leave the long marquee along Carlton Street intact as it's the best and most explicit historic plaque in the country. What a font. Though it's big, because of its urban location, it doesn't seem big enough to hold the capacity it does inside. It's such an efficient use of space. And apologies to Montreal, but on Saturday nights for so many years, this was the centre of Canada."

Honest Ed's
The essence of colloquial architecture, if you'll pardon my Latin, this Bloor St. bargain emporium is more sign than structure, though the current version is far more polished and unified than any time in its raucous, garish past. It's the point where Toronto is nearest to Vegas though, tellingly, it's an institution devoted to thrift, not risk.

"An undeniable landmark of the undeniably vibrant Annex and Koreatown," writes Graeme Stewart. "It is one of those icons and institutions that once you've experienced it, you'll never forget, and is representative of many layers of Toronto's history."

Palace Pier
The twin towers of Toronto, although their '70s luxury condo heritage is more likely to evoke turtlenecks and key parties than financial giants astride the city. In an age before amalgamation, they were the signpost for the city's westernmost border, and the gateway to Etobicoke, the eternal garden suburb. "At the mouth of the Humber River," writes Shawn Micallef, "these two (originally just one tower) are the markers for people entering and leaving the city."

"For many years they stood alone above Etobicoke's lowrise skyline, but now with the addition of new condo towers where the old Motel Strip was, we've got an almost Chicagoan 'Gold Coast' city-scape out here. Unlike that famed highrise neighbourhood along Lake Michigan, it isn't separated from the water by wide Lake Shore Drive as our Lake Shore Blvd is on the city-side. The Palace Pier towers, with their smoky disco-era glass still are the tallest around and are the ones who decide when we're in and out."

Ashbridge's Bay Pumping Station T
Like a Martello tower in a Jetson's landscape, this drum-like utility building has style to spare, and has long been a favourite of photographers. Fans were outraged to discover that its crenellated roofline was altered as part of a city project to upgrade this east end sewage treatment facility and remediate the lingering odours for which it's long been notorious.

There are many who wish that a building this fabulous did more than pump sewage, and Shawn Micallef says he's fond of misinforming visitors to the city that Pumping Station T is actually the city's nonexistent mayor's residence, and it is - in an alternate timeline when this would actually have been a stunning counterpart to Viljo Revell's New City Hall.

What did I miss? Add your top Toronto landmarks to the comments.

Photo of CN Tower by Chris Seifert in the blogTO Flickr Pool.