Final two photo clues for Mill Park Mystery

I have enjoyed sharing photo clues with you connected to my new book, Mill Park Mystery.  Even though the story is a total fiction I have been to all the places shown in the previous photo clues.  

Over the weekend I made my kindle version of Mill Park Mystery available as a FREE download and interestingly enough 107 individuals did take advantage of the offer.  The breakdown of where the individuals downloaded their free book from is as follows: 85 from Amazon/US, 14 from Amazon/UK, 6 from Amazon/DE, 1 from Amazon/JP, and 1 from Amazon/CA. I would like anyone that downloaded their free book from one of the listed locations to send me an acknowledgement indicating the city where they live.

Now for the final photo clues!  

What is significant about this tower?

Do you think the above tower lead Philso and Cornelli to their final clue?  And, why?

Why is this door an important clue?

Who is that lady?  Is she part of the story?

Now for the final clue!  The first individual that responds to this final photo clue (as to its importance and what it leads to) will receive not only a FREE signed copy of Mill Park Mystery, but free signed copies of my two "life series books" Gibbon's Secrets and Back in the Day.

                                    

The final photo clue!  

Why is this important and what does it lead to?

Now that photo clues are complete and its up to you to comment below with the correct answer to receive your free signed copies.  All you need to do is to buy the book and the clue will be revealed to you.  Mill Park Mystery is available on Amazon so the rest is up to you.  Good luck in your discovery?