So much about New Korea is unknown—the progress of its nuclear weapons industry, the hierarchy of its power elite, the range of its missiles, the extent of its industry hidden underground. And now the world is wondering if ruler Kim Jong Un will follow through on the fireballs of threats and ultimatums he issued this week after the UN imposed new sanctions. Following are a few of the things we do know about a country that seems to have retreated into a very dark corner.

Geography: Eighty percent of North Korea is covered by mountains and uplands. When drought or heavy rains hit, the limited amount of agricultural land is stressed, contributing to regular food shortages.

Life Expectancy: North Koreans live an average of 69 years, 11 years less than South Koreans. The greatest health threat is hunger. In the mid-1990s, a famine killed some 2.5 million people, or roughly one in 10 citizens. According to a recent UN report, two-thirds of the population do not know where their next meal will come from.

Border controls: The 148-mile-long border between North and South Korea is the most heavily militarized in the world. It is estimated that at least a million of the 25 million North Koreans are in uniform, many of them bullying and spying on their own citizenry.

Entering and exiting: Soldiers have orders to shoot anyone trying to sneak into or out of the country. China is the most widely used escape route. Approximately 80 percent of the North Korean refugees attempting to flee through China are women.

Gulag: An estimated 200,000 people in North Korea are held in secret camps for political prisoners.

Holidays: April 15, the birthday of the country's late founder, Kim Il Sung, is considered the most auspicious day in North Korea, officially declared as the "Day of the Sun." Celebrations take place throughout the country, including events such as large-scale synchronized dancing. In 2012 the centenary celebrations of his birth cost an estimated two billion dollars.

Fake money: North Korea has been accused by the U.S. government of running one of the most sophisticated counterfeit operations in the world. They are rumored to have bought an intaglio press at a cost of over seven million dollars—the same kind of printer the U.S. government uses to print its money. The counterfeiting operations reportedly specialize in "Franklins," or hundred-dollar bills.

Fashion: Wearing jeans is a crime. Denim symbolizes the enemy United States.