this is almost a phiolosophical question - bases of national unity are very broad - common language, religion, culture, geographic proximity, and many others are the bases of national unity
the national game (sport) of Nepal is dandi biyo.
Nepal National Library was created in 1957.
National Museum of Nepal was created in 1928.
National Assembly of Nepal ended in 2007.
National Assembly of Nepal was created in 1990.
There isn't any national fruit in Nepal.
national unity brings progress in a nation
Russian National Unity was created in 1990.
Union of National Unity was created in 1833.
Camp of National Unity was created in 1937.
National Unity - Peru - was created in 2000.
Committee of National Unity was created in 1977.