Great idea! a cool innovation for my city! honestly, I'm planning to build a new city centered around the monolith :))
However, to be more "realistic", it should be much smaller. And I think the width should be smaller compared to the height.
Also, the ground is... ahem... boring. It would be perfect to put the monolith into a desert-like roky pit or something like that. Just sticking to the film... :)