En.
"En" means "in, inside;" when "n" is added to the noun which it
precedes, it means "into", as "Kie vi estas? Mi estas en la domo. Kien
vi iras? Mi iras en la gxardenon." Where are you? I am in the house.
Where are you going? I am going into the garden. "Malamiko venis en nian
landon", An enemy came into our country.