Before entering my question,
I have to say that I have already asked a similar question today. However it contains some grammar errors so that it is not very good for a discussion about how to break down the use of "where" and analyze it.
I asked this new but similar question because the previous post has some valuable feedbacks I think would probably be helpful to other learners so that I don't want to close it or delete it.
Now, entering my question:
I am not sure my analyzing the use of "where" in the examples (1), (2), (3) and (4) is correct. Is my analysis correct?
The example (3) and (4) are the ones that sound wrong to me, but I remember some books say "where" can be "which...in/at/from".
My analysis:
(1) This is a private beach, where its members play balls and take a sunbath when the weather is good.
is equal to
(2) This is a private beach, at which its members play balls and take a sunbath when the weather is good.
is equal to
(3) This is a private beach, which its members play balls and take a sunbath at when the weather is good.
might also be equal to this one??
(4) This is a private beach, which its members play balls at and take a sunbath at when the weather is good.