"Um dia vou conhecer os castelos na Inglaterra."
I think it's a common confusion for Spanish and Portuguese speakers learning English as well. When they are first learning English, they might say to me "Do you know Spain?", and I know exactly what they are trying to say. They are trying to say "Have you ever been here?". This sense of "know" should really be translated as "acquainted". Of course, English speakers don't normally say "I have been acquainted with the castles of your country", unless they have been brought up to speak like this or they are just being poetic. But, regardless, "conhecer" (and conocer in Spanish) try to translate the idea of getting to know a place by visiting or experiencing it first hand. I hope this helps :)