Bellevue, like Bedlam, Billingsgate, and the Bastille, is an actual place that, in the general discourse, has attained the status of an abstraction. The hospital can trace its origins to 1736, and is thus one of the oldest hospitals in the Western Hemisphere. The name is French, of course, for “beautiful view or prospect.”

This pleasant and auspicious name was chosen in 1825, almost 90 years after the hospital’s foundation, to inspire bucolic visions and so allay the all-too human fears of those who entered. But in due course, as the world knows very well, Bellevue came to mean an insane asylum, a house of modern horrors in the manner of Francis Bacon.

This impression was only enhanced by the fact that it – as opposed to more upscale hospitals like NYU-Cornell, just down the block, or Columbia Presbyterian in Washington Heights – has always cared for the poorest sectors of society.

Now, in hopes of burnishing its image, Bellevue is set to open its brand new Ambulatory Care Pavilion and so, through architecture, to improve its standing in the world.

Such improvements could not have come soon enough. Rarely has architecture displayed more power to suggest order or its anarchic opposite than in the present entrances to Bellevue. On a recent visit, I entered what I initially took to be a back door, but that proved to be the main entrance. Once inside, I had to shift for myself through a warren of interminable halls.

Though I was one of the few people who was neither sick nor visiting the sick, I too felt as though I were being drawn into the almost Gothic gloom of the place – a modern Aalto-esque Gothic, expressed in the arid rationalism of its low-lying ceilings and drably colored rubber floors.

You would never know it now, but the campus of Bellevue was designed by McKim Mead & White, who sought and briefly achieved an effect precisely opposite to what we see today. The majestic symmetry of the place they created effortlessly communicated a benign and orderly competence. The main building, completed in 1940 in a dignified classical style, received the visitor along a grandly landscaped carriage path. In short, McKim Mead & White instantly understood what was needed, the consolation of harmonious order, and they delivered it.

All of that changed in the 1960s and 1970s, when things began to go seriously, inexcusably wrong. The corrosive tastelessness, the collusive mediocrity, the self-satisfied banality that brought us the Port Authority bus station and Madison Square Garden programmatically dismantled the paternal grandeur of the master plan, replacing it with an asymmetrical mess. Bellevue’s architecture conveyed in microcosm the morass into which the city had then fallen, and in macrocosm the confusion and dismay of all who entered.

As the great, centralized entranceway was closed off, visitors were henceforth channeled through an ignoble doorway that protruded in a tangent from the main building. Some of the grander, older wings were unceremoniously imploded and never replaced. But the greatest indignity of all was a multilevel parking garage that concealed all evidence of McKim, Mead & White’s building.

In the history of architecture, it is unclear that any generation has wrought a more dishonorable vengeance on an older and finer generation than was accomplished here.

The new Ambulatory Care Pavilion, on First Avenue between 27th and 28th streets, was designed by Pei Cobb Freed & Partners and stands in the position formerly occupied by the garage. And though its five-story glass-and-steel curtain-wall will win no awards for innovation or design, at the very least it is not an eyesore.

Both functional and commodious, it restores some measure of grandeur to the entrance envisaged by McKim Mead & White. The only vaguely challenging element of the exterior is its angled southern tip, relative to the pale, brick structure behind it, which contains the core of the building. This proves, by the way – if proof were needed – that the deconstructivist style, once seen as radical, has now become the default mode of contemporary architecture.

What is very good about the project, however, is its interior. Passing through an entrance of transparent glass, you come to a spacious overhang defined by large pylons. This opens out to a 90-foot high white atrium that curves in a dramatic parabola. It has granite flooring and is roofed with a massive sloped skylight. And there before you, as though redeemed, is the 1940 entranceway.

Several things are symbolically achieved by turning what was outdoors indoors. The first is to create the pleasing, though hardly unprecedented incongruity of seeing a building’s facade inside another building, where it is not supposed to be.

Then there is the sense, especially among those who are aware of what indignities this building has suffered, that a younger and more vital generation has taken the responsibility of extending its protection over an older and more enfeebled one. Finally, it establishes a new context for the older building, as though placing it in a vitrine in a museum.

Here, no less than in the Meatpacking District or Chelsea or parts of Brooklyn, the decaying remnants of time past are redeemed as cultural relics. The mere process of cataloging, documenting, and measuring has the effect of transforming and ennobling what was once debased.

This museological consciousness extends to each floor of the new structure, which shows archival photos of Bellevue’s past, enlarged and silk-screened across its walls. Smaller images adorn the passageways. Soon there will be a substantial museum on the premises to set forth more than two and a half centuries of Bellevue’s existence.

Even if most New Yorkers would never believe it, Bellevue Hospital deserves their most reverent attention. It purchased in 1794 a lease on property along the East River and it has remained there, exactly there, ever since. Imagine, as in a time-elapsed film, the transformations Bellevue has undergone in all that time and, even more important, how the city has grown up around it, transforming the dirt paths of the countryside into cobblestones, followed by concrete, street-lamps, and high-rises.

I do not believe that anything remains of its earliest foundations, and most of the beauty of earlier days has been torn down or covered by the crudest interventions of the most tasteless bureaucrats. Brutalized and deformed, Bellevue might stand as an emblem of what New York City, at its harshest, can do to those who, at their weakest, are unable to withstand the urban colossus that takes all before it.

In this context, its spacious and well-lit new pavilion proves that, on the whole, the present generation of architects are somewhat better at design than the generation of 40 years ago and one thousand times more sensitive to the past and to the blessed amenities of life.