This is the 4057th most frequent Turkish word.
gölü
"Gölü" means "the lake" in English.
Here, 'gölü' is used as a direct object in the accusative case to denote the specific lake the speaker likes.
Ben gölü çok seviyorum.
I really like the lake.
In this sentence, 'gölü' is used in the accusative case to indicate the object of the action 'watching'.
Doğanın güzelliğini gölü seyrederken anladım.
I understood the beauty of nature while watching the lake.
Here, 'gölü' is again in the accusative case, denoting the lake that was visited by the tourists - a specific object of the verb 'visited'.