The majority of tourists enter Mongolia through three entry points. By flight to the capital Ulaanbaatar (Ulan Bator). By train or car from China (Zamin-Uud border crossing). By train or car from Russia (Sukhbaatar/Altanbulag).
See the detailed Google map of all the border crossings, with data on each crossing. Zoom in and click the icons to see details.
Following is a description of - flight, train, road and trade border crossings.
All International flights land at Chinggis Khaan airport in Ulaanbaatar, with one exception - flights from Kazakhstan land in Olgii in west Mongolia, tourists are permitted to enter Mongolia through Olgii, with this flight.
A flight from Hailar in China does have a stop over in Choibalsan in east Mongolia, before reaching Ulaanbaatar, but tourists are not permitted to get off at Choibalsan.
For more see the Flights page - all airlines and all flight options into Mongolia.
For more see the TransMongolian train page for detailed train options.
The Zamyn-Uud/Erlian from China and Altanbulag/Kyakhta from Russia, have full services for tourists. The others have limited services. The main issue is limited options for transportation to, from and across the border. You may use one of these, if you enter with your own car, bike, or pre-arrange for someone to meet you and take you across and beyond the border crossing. Crossing by foot is prohibited.
The general rule is that border ports are open weekdays 10:00-17:00
some are open 24h, and some open on weekends too.
All road border crossings are closed on national holidays.
(Train and flights operate all year round).
Dates of closed borders: New year January 1st, three days of the Chinese lunar new year (annually occurs on different days of the month). May 01-03, October 01-03, two days of the Mongolian lunar new year (annually occurs on different days of the month). March 08, June 01, July 11-12, and November 26 annually.
Tourists can not enter through any of these crossings. They are used for trade mines export, and for locals with Chinese or Russian passports.
In addition to these there are several temporary border crossings used by local herders. For complete details see the Google map.