Not sure what you are looking for, UDC-- the appropriateness of the thesis sentence, or its grammatical correctness.
If your paper is going to describe and discuss the main historic buildings (mostly accommodations-- but surely the Lighthouse is included!) in St. Augustine, then it is appropriate.
Linguistically, 'grasps' is wrong; I would suggest something like 'enfolds' or 'incorporates'.
Hope this helps.