{Entry & Exit Formalities}
Nepal provides a visa-on-arrival facility. All you need is 2 passport-size photos. The fee is USD 25 for 15 days multiple entry visas and USD 40 for 30 days multiple entry visas.
Nepal is committed to making things simpler for foreign tourists. Visas on arrival are provided at the Tribhuvan International Airport, Kathmandu, and as well as at all land border crossings open to foreigners. All you require is passport-size photos and currency in foreign domination preferably US dollars. Your passport must be valid for at least six months and you also will need a whole free page for your visa.
To get more details on the matter you can always visit the below site. http://www.nepalimmigration.gov.np/