Obtaining a Visa for Mongolia is a relatively painless and quick process. Visas are available for various periods of time but as a tourist a 60 day single entry visa is the norm, any longer would require an invitation letter and a clear statement of purpose concerning your stay in Mongolia. For a 60 day single entry visa an invitation letter is not normally necessary. Should an invitation letter be required, most travel agencies will provide you with a confirmation of your bookings with them which should do the trick.