As you may have heard (it was in all the papers!), the Government of Nepal opened a formal embassy in Ottawa. Canadian citizens using a Canadian passport require a visa to visit Nepal. These visas are usually issued at the airport in Nepal.
Tourist visas may be purchased in advance or can be bought in Nepal upon arrival at either Tribhuvan International Airport, Kathmandu; Biratnagar (Jogbani), Birgunj (Raxaul), Bhairahawa (Sunauli) and Kakarbhitta (Panitanki) on Nepal-India border and Kodari on Nepal China border.
Click here for a Nepal visa.