Mongolia is a huge country. It's twice the size of Texas and nearly the size of the European Union.
But there are only 3 million people in the whole country.
That gives Mongolia one of the smallest population densities in the world.
More than a third of the population — 1.3 million people — live in Ulaanbaatar.
The city is a mix of high rises, low rises, and "gers" — a kind of tent.
Ger districts surround the downtown areas and are home to rural and nomadic Mongolians who move to the capital to seek work.
Many have no running water.
In front of Ulaanbaatar's Parliament House is a statue of Damdin Sukhbaatar, the leader of Mongolia's 1921 revolution.
The city square was originally named after Sukhbaatar. It was briefly changed to be named after Ghengis Khan, but a court ruled it had to be switched back.
This is a giant statue of Genghis Khan at the Mongolian Parliament House.
Conqueror Kublai Khan, grandson of Ghengis Khan, is also a source of intense pride in Mongolia.
Ulaanbaatar suffers from heavy air pollution from the coal it burns for heating and cooking.
Heating is vital in Ulaanbaatar, which is the coldest capital city in the world.
Winter lows can reach -40C (-40F). Balconies and car boots can suffice as perfectly good meat freezers.
Because it is so inhospitable for large chunks of the year, hotels and transport may have more availability than other cities to potentially manage a last minute influx of diplomats and press for the Trump-Kim summit.
This is the international airport in Ulaanbaatar, which is named after Genghis Khan, where Air Force One could land. Kim could fly, or travel to Mongolia in his armored train.
The country has tried to maintain friendly ties with most countries.
Mongolia sees itself as neutral. Earlier this year it celebrated its 55th year of diplomatic relations with the UK with an ice sculpture of The Beatles.
Ulaanbaatar has hosted bilateral talks between other countries in the past, including North Korea and Japan.
Talks have taken place at Ikh Tenger, the residence of the Mongolian president.
Mongolia's President Khaltmaa Battulga is also a martial arts expert, while the country's Prime Minister is the head of a Harley-Davidson fan club.
Nearly 1,200 North Koreans lived and worked in Mongolia until the UN introduced new sanctions last year. The first workers began returning home in December.
But many North Korean defectors also head to Mongolia, via China. Once a defector arrives, guards call the South Korean embassy in Ulaanbaatar which hosts defectors until it can take them to Seoul.
The ties between the two countries go back to Mongolia's communist days. Just outside of Ulaanbaatar some students still attend a school that was built by North Korea more than 50 years ago.
A baby boom in Mongolia has led to an undersupply of kindergarten spots, which are given out by a lottery system. Admission tickets are pulled out of a box in front of parents at random.
Some 16,000 child jockeys take part in hundreds of horse races every year. The races are part of Mongolia's strong horsemanship traditions, but have been slammed by human rights groups and banned by courts.
Google Street View was only launched in Mongolia in 2015.
In 2016, Mongol Post partnered with the startup what3words to give every location, as small as 3 metres x 3 metres, a unique identifier. One section of the Ulaanbaatar railway is identified as "pricing.drizzly.potato."
Ulaanbaatar has played host to a number of US politicians in the past, including Secretaries of State John Kerry and Hillary Clinton.
President George W. Bush and Vice President Joe Biden have also visited the country.
Mongolia was the second communist country in the world and had strong ties to the Soviet Union. Many students still learn Russian.
Mass demonstrations helped overthrow the communist rule in 1990, and the last statue of Lenin in Ulaanbaatar was torn down in 2012.
Buddhism has now made a resurgence in the country, and half the population identifies as Buddhist.
One of Mongolia's most iconic sports is eagle hunting, where eagles are trained to hunt animals. But there are so few eagle hunters left, the tradition could die out within a generation.
