The most and first asked question in person or on the net is: where is Mongolia. Yes, Mongolia was in some sense so big that it was everywhere from Korean peninsula in the east all the way to the west, Mediterranean, that was 13th century Mongol Empire.
But today Mongolia "shrinked" into 6th largest country in Asia and 19th in the world. Not too bad. If you are traveling by land, there is only two entry points to the country from Russia from the north and China from the south.
The following are the words of a traveler who entered Mongolia from Russia: "The trip from Irkutsk to Ulaanbaatar in Mongolia takes about 27 hours, but most of it is actually spent stationary. The scheduled border crossing stop takes a mind numbing six-hours-and-fifteen-minutes, which is divided in four and a half hours at the Russian border, and another one hour three quarters at the Mongolian.
Not that we cared though, we ended up having a great party with two guys from New Zealand and two girls from England. We weren't sure how much alcohol we were allowed to bring across the border, so we made sure to drink all the beer, wine and vodka, just as a precaution."