Why are different places similar?

For an inordinately vague question, you get an appropriately vague answer: Because similarities exist. More specifically, different places share the attributes of their underlying structures. i.e. All places on Earth have the same basic atmosphere. Also, the human psyche tends to categorize experiences based on their differences and similarities to other experiences. Any two places examined by the same person will conjure up similarities in the mind. However, the answer that best fits the Wording of the question is that the fact that they both different is a point of similarity.