Russian doesn't have a separate preposition to match English "to" when talking about the direction of movement. Instead it uses the same one that is used when someone or something is there, while changing the case of the place from prepositional to accusative.
"The girl is on the beach." - "Девушка на пляже."
"The girl runs to the beach." - "Девушка бежит на пляж."
"Vera is in the school." - "Вера в школе."
- "Vera runs to the school." - "Вера бежит в школу."