There are four border crossings open to foreigners, three by the Russian border and one near the small town of Erlian on the border with China.
To stay in the country a visa is required. The process for getting a thirty day visa is relatively painless, requiring a simple form and a small fee at your local Mongolian embassy. Longer visas are available, but require an invitation letter from a Mongolian company. These can sometimes be arranged through tour companies. Also, it is possible to acquire an expedited visa in a matter of hours at the Mongolian consulate in Erlian, though there is a steep $50 US fee for this service. A similar service is available in the Mongolian consulate in the Russian city of Irkutsk.
As of September 2008, a visa is required for everyone not a citizen of the following countries:
USA, Kazakhstan, - visa not needed for a visit not exceeding three months. Any stay past one month, however, must be noted upon arrival.
Cuba, Israel, Lao PDR, Malaysia and Thailand - visa not needed for a visit not exceeding one month.
Philippines - visa not needed for a visit not exceeding three weeks.
Singapore - visa not needed for a visit not exceeding two weeks.
Democratic People’s Republic of Korea, and Republic of Korea -those with diplomatic passports need no visa for a visit not exceeding one month.
India - requirement of Mongolian visa without visa fee .
Hong Kong - visa not needed for a visit not exceeding 14 days ID cards are accepted to indicate residence in Hong Kong.
For more than 30 days tourist visa you will need invitation letter (http://www.steppesjourney.com)
The Embassy of Mongolia website (http://www.embassyofmongo...) is useful for updates.
The Embassy of Mongolia's China website (http://www.mongolembassyc...) you will need if you are applying for your Mongolian visa in China. You can print off the application form from this website, although the consulate does have them.
By train
The Trans-Mongolian Line of the legendary Trans-Siberian Railway links Mongolia's capital Ulaanbaatar with Moscow and Vladivostok, Russia and Beijing, China.
There is a small water boiler at the end of each train car which dispenses free hot water, so it's a good idea to stock up on instant noodles and tea for the trip. Also, don't expect to encounter any English-speaking staff on the train or in the stations.
By road
The road stops at the border town of Zamyn-Uud and gives way to an open desert, with tracks going in various directions but generally heading north toward the capital city. Hitchhiking in Mongolia is not easy and a little bit of money can be expected. There is an average of one car every hour heading into the desert. Expect a bumpy road with not much to see -- but this is the real Mongolian steppe.