The Superior Dome

At 536 ft. across, The Superior Dome has the largest diameter of any wooden dome in the world.

The dome is an integral part of Northern Michigan University's sports complex. The flexible space, with a retractable artificial turf, can be reconfigured for football, volleyball, hockey, tennis, track and field, or a number of other sports. 

Structurally, it is a geodesic dome -- this means that it is a self-bracing framework of triangles. A main feature of a geodesic dome is that the dome is built from a minimum of structural elements (in this case, 781 massive Douglas fir beams) to achieve the great strength of a dome.

Although some of the decking is covered by acoustic panels, nearly every part of the wooden structure is visible, and it's striking and lovely to look at. 

When no events are on the schedule, dome visitors are free to go pretty much wherever they please -- you can run around like a maniac on the artificial turf or climb the bleachers to get a closer look at the ceiling.  Locals often use the space for walking laps (many of them use the circular exterior hallway as well). When required, the building can hold as many as 16,000 people. 

In addition to the massive central space, the dome houses various exhibits, training facilities and offices, including those of the United States Olympic Education Center.