Some of the buildings out there are really strange and usually produce amazement and admiration towards the designer. Well, this one is most notable for its weirdness and its true beauty is hard to appreciate unless you have a really strange art sense.

The AT&T Long Lines Building is a truly unique building, not because it's the tallest, the largest, or the most technically advanced. In fact, it's not even habitable, as it doesn't house apartments or offices. The 167.5 meter tall skyscraper was built to house telephone switching equipment and was completed in 1974.

Located on Church Street, in Manhattan's SoHo neighborhood, the building is shocking the viewer through its lack of windows and flat concrete slab facade. It kind of looks like a medieval tower, like those linking together portions of a defense wall of an ancient castle.

Even on the inside, the building is strange, because of the fact that the average floor height is 6 meters (18 feet), considerably taller than in an average high-rise. They are also unusually strong, designed to carry 200 to 300 psi live loads. (13 to 20 atmospheres), required by the heavy equipment it contains.

The concrete slab is clad in pink-colored Swedish granite and has six large protrusions which rise to the top, giving the building a castle-like appearance. They actually house air ducts, stairs and elevators.

The architect, William H. Whyte claimed that it features the tallest blank wall in the world. It is also one of the finest examples of the Brutalist architectural style, spawned from the modernist architectural and inspired largely by the work of the Swiss architect Le Corbusier.

It may not be appreciated by most non-specialist and it does require a certain amount if twisted thinking to find it beautiful, but it's this unique and intriguing aspect that makes it one of the most interesting buildings in the world, a refreshing alternative to the steel and glass skyscrapers in today's landscape.