From August 10 to October 10, U.S. passport holders will be able to get visas to visit North Korea. A handful of tour operators are offering packages for this brief and rare window. During these two months, the Arirang Festival and the Mass Games will be held. The Guardian (U.K.) calls the Arirang Festival "one of the greatest, strangest, most awe-inspiring political spectacles on earth." The Mass Games are a synchronized gymnastic event involving thousands of people.
It's general knowledge that travel to North Korea is usually nearly impossible, but until reading up on the topic I didn't realize it was because of the difficulty of getting a visa from North Korea, not because of any travel restrictions placed on U.S. citizens by the their government.
Trips are being offered by Asia Pacific Travel, Ltd.'s NorthKorea1on1, Geographic Expeditions, and High Country Passage. Trips are expensive, running between $4,000 and $6,000 per person excluding airfare.
There are links to articles about North Korea festival travel from the New York Times, USA TODAY, CBS, and a bunch of other outlets. They offer political context and practical advice, and if the possibility does strike your interest, reading up is probably a good second step.