The Triangle is a hotbed for modernist buildings

The Triangle is home to dozens of modernist architecture gems, from arenas on the state fairgrounds to homes deep in the woods of Durham.

There are four qualities that are staples of modernist architecture, according to George Smart, the founder of the Durham-based USModernist.org

1. A flat or low-pitched roof.
2. The building has an unusual geometry, i.e. it is not just a box.
3. An abundant use of windows and light sources.
4. An open floor plan.

Be smart: North Carolina has a significant concentration of modernist buildings due to the founding of N.C. State University's architecture school in the 1940s. The school brought together some of the leading minds in the field at the time, Smart said.

Axios spoke to Smart about what he believes are some of the most important modernist buildings in the Triangle.

Here are his picks:

J.S. Dorton Arena in Raleigh

Perhaps the most well known modernist building, the arena is on the state fairgrounds in Raleigh. It was once a livestock pavilion but is now a 7,000-seat arena used sporadically for fair events and, in 2016, a Donald Trump rally.

Details: Dorton Arena, completed in 1952, was designed by Matthew Nowicki, who was acting head of N.C. State's architecture school until his death in 1950.

• Many believe that Nowicki would have become one of the more influential architects of the 20th Century if not for his early death at age 40 in a plane crash.

What they're saying: Dorton's "revolutionary 1950 design … with intersecting concrete parabolic arches that support a network of cables holding the saddle-shaped roof, was so unique that it was known throughout the world as the 'Raleigh arena,' according to the report "The Development of Modernism in Raleigh, 1945-1965."

Henry L. Kamphoefner House in Raleigh

In 1948, Henry Kamphoefner became the first dean of N.C. State's College of Design. He was also the reason so many notable architects moved to the Triangle. His home in Raleigh was one of the first modernist houses in the area.

Details: The home was designed in 1948 by Kamphoefner and George Matsumoto, an N.C. State professor who would become a notable architect in his own right.

• The famous American architect Frank Lloyd Wright stayed at the Kamphoefner house once, Smart said.

James B. Hunt Jr. Library in Raleigh

The Hunt Library on N.C. State University's Centennial Campus is one of the more notable public projects built in the Triangle in recent years.

Details: The library was completed in 2013 and was designed by the Swedish architecture firm Snøhetta.

What Smart's saying: "You can just tell it was very thoughtfully designed. When you walk through it, you're immediately struck with the care that went into making this a functioning library for the 2010s."

Cassilhaus in Durham

Built in the forests between Durham and Chapel Hill, this personal residence has become an important gathering place for designers and artists in the Triangle, Smart said.

Details: Cassilhaus opened in 2010 and was designed by the Durham architect Ellen Cassilly.

• It hosts artist exhibitions, a collection of modern art and residencies for artists from around the world.

Rantilla House in Raleigh

Located in southwest Raleigh, this is another recent construction that won numerous design awards, Smart said.

Details: Built in 2008, the home was designed by architect Mike Rantilla, the Triangle director for the firm EwingCole.

• Rantilla worked with the late Durham architect Phil Freelon and was heavily involved with the design of the National Museum of African American History and Culture in Washington, D.C., according to U.S. Modernist.