This is the 1644th most frequent Russian word.
европа
Europe.
Here, 'Европа' denotes the geographical entity of the continent.
Европа — это континент, находящийся на северо-западе Евразии.
Europe is a continent located in the northwest of Eurasia.
In this sentence, 'Европу' is used in the accusative case to indicate an object of a dream or desire.
Я мечтаю посетить Европу и увидеть ее достопримечательности.
I dream of visiting Europe and seeing its landmarks.
'Европы' here is in the genitive case, denoting possession or association.