Producer-ish Thought of the Day

So from time to time, I find my producing classes infiltrating on my sanity. Today I had this thought:

If I wanted to build an Eiffel Tower (a la the one in Vegas), what rights--if any--would I have to buy?

Think about it. Is the actual design copyrighted? If I added a column or zigged instead of zag, could I get away with it? Is it considered a work of art, even though it's actually just a famous radio tower? (By the way, if you have any pictures of the light show on the E.T., you're infringing on copyright. You have to pay the SNCF royalties.) Questions questions questions.