In the '60s and '70s, architect Vincent G. Kling practically had a lock on big projects around Philadelphia's City Hall. His firm designed the Municipal Services Building, Centre Square, the ill-starred One Meridian Plaza, as well as the original Love Park and Dilworth Plaza. Kling's firm so lorded over the area other architects jokingly called it the "Klingdom."

Thanks to his knack for winning commissions, Kling built his architecture practice into the largest firm in Pennsylvania. Yet he never achieved the renown of contemporaries like Louis Kahn, Robert Venturi, or Robert Geddes, probably because his buildings were considered too derivative and too corporate.  That they were, but they could also be stylish at the same time.

One of his most impressive designs is many miles from the Klingdom, just off the Valley Forge interchange of the Pennsylvania Turnpike. Built for a consortium of Baptist organizations in 1962, the three-story office building is a futuristic white ring set in the center of a 55-acre wooded campus. When it opened, the area between North Gulph Road and First Avenue was still farmland, and many a passing motorist must have wondered whether an alien spaceship had touched down in the Pennsylvania suburbs.

While this was the era of round buildings, the shape of the American Baptist Convention, as the offices were originally known, grew out the denomination's philosophical commitment to local autonomy. Baptists don't have a governing body, and every Baptist church and mission operates independently. When five local Baptist organizations agreed to pool resources to build a shared home in King of Prussia, they asked Kling to come up with an anti-hierarchical design that would express equality and unity.

His solution was a continuous ring divided by stair towers into five segments. The building was quickly nicknamed the "Holy Doughnut," although employees also liked to call it the "Baptist Bagel," and airline pilots referred to it as "the elephant's toilet seat."

Those who have glimpsed the doughnut/bagel only from a car window don't know what they're missing. At street level, Kling embedded the offices with a light-hearted, Googie charm that was typical of midcentury modernism. The entrance is marked by a concrete pleated canopy reminiscent of the those at roadside drive-ins. That same accordion form is echoed in the arcade that Kling carved into the building's ground floor.

Kling repeats the triangle theme elsewhere in the building. The third-floor windows terminate in sharp peaks, giving the building a vaguely Gothic flavor that seems appropriate for a religious group that emerged from the Church of England. Even with those subtle references to traditional styles, this is an edgy building for a main-line religious group.

The American Baptist offices are equally interesting when viewed from above. A curving, single-story structure acts as a lone parenthesis, bracketing one side of the office ring. The parenthesis, which housed presses for the Baptist publishing house, also features a pleated roof and triangular windows. In its heyday, more than 700 people worked in the 250,000-square-foot compound. At lunch, they would sprawl on the grass lawn inside the ring.

It's hard to look at Kling's giant office ring and not think of a more recent design, the circular Apple headquarters by Norman Foster that opened last year in Cupertino, Calif. Like the American Baptist Convention, it dominates a confluence of suburban highways.

Today, the King of Prussia site has evolved into series of concentric rings, with wedge-shaped parking lots encircling the main building. In 1984, the American Baptist Convention sold off part of the land to a developer, and four standard-issue, rectangular office blocks were inserted between the lots.

Sadly, as church membership has dropped off, the Baptist Convention — now called American Baptist Churches USA — decided to sell its big doughnut. Most of the original organizations have moved out, and a sale is said to be imminent. The property is listed on the National Register, but that honor does not guarantee the design will be protected. With appreciation for Kling's work growing, let's hope the next owner doesn't try to reinvent the wheel.