While most '50s and '60s imaginings of future architecture didn't pan out, there are some futuristic-looking modern buildings that fit the bill. We'll show you some amazing examples of "future-tecture" in this gallery.

While most '50s and '60s imaginings of future architecture didn't pan out, there are some futuristic-looking modern buildings that fit the bill. We'll show you some stellar examples of "future-tecture" in this gallery.

A decades-old building as futuristic? Absolutely. Although The Sydney Opera House was first designed in the late 1957 and built in 1973, it's still considered an amazing building and is an iconic part of Sydney's harbor. So much so that it was designated a UNESCO World Heritage Site in 2007. It was also one of the first examples of a building designed with CAD (computer-aided design).

While this building has a normal name, 30 St. Mary Axe, nobody calls it that -- it's the Gherkin (or something more risqué). Opening in May 2004, the building is eye-catching for its unusual shape and diamond-shaped glass panels. It also happens to be energy-efficient, with shafts running through each floor to provide ventilation as well as insulation and heating. While it functions as an office building, there's also a restaurant, bar, and private dining available.

The Klein Bottle house is based on a mathematical concept: a non-orientable surface (meaning, there's no boundary and no notion of left or right). To turn this into a livable home, the firm of McBride Charles Ryan interpreted the Klein Bottle into an origami-like structure, while still retaining its spiral qualities. A staircase winds around an internal courtyard, with bedrooms as offshoots, until ending in a living space at the top.

The Walt Disney Concert Hall was built in part using funds donated by his widow, Lillian. The hall is typical of architect Frank Gehry's style, with a twisting form covered in a stainless steel skin. While the steel makes the building even flashier, Gehry originally designed it with a stone exterior. As a bonus, the Los Angeles Philharmonic and its fans love the acoustics of their new performance space.

The Burj Khalifa, the tallest manmade structure in the world, rises 2,723 feet (830 meters) in Dubai, United Arab Emirates. It's so tall, in fact, that engineers had to design a new structural support system. Its three-lobed design, radiating around a central core, is based on the Hymenocallis flower, but it also incorporates parts of traditional Islamic architecture. So nature, culture and history all come together in an aluminum and stainless steel tower that includes both offices and residences.

The Air Force Academy Cadet Chapel is another oldie but goodie -- completed in 1963, it's as iconic and futuristic today as it was then. Seventeen spires rise on a tubular steel frame of 100 identical steel tetrahedrons, with colored glass mosaics in one-foot spaces between each spire that create a glowing line effect when viewed from within. The chapel includes worship spaces for five different faiths, and although it was controversial at the time, it's now a U.S. National Historic Landmark.

Called HSB Turning Torso, this Malmo, Sweden, skyscraper incorporates a 90-degree twist and is based on a sculpture of a twisting person called "Twisting Torso." Nine segments of irregular pentagons stack around a central core, with the final pentagon on top a full 90-degrees clockwise from the bottom pentagon. It includes both office space and apartments, and the public can also tour it.