Nicolas Fouquet???

Correct. Fouquet built Vaux le Vicomte only to raise the jealousy and suspicion of Louis XIV. However, Louis was so impressed by the chateau that he hired the architect and landscape designer to redesign Versailles.
On Saturday nights from May to October, the entire chateau is illuminated with candles. It is a breath-taking sight.
If you want to take a look here is the link...
http://www.vaux-le-vicomte.com/eng/accueil.htm

cmt?

Sorry, I was out and then forgot.

According to legend, a nymph emerged as a spring, located in an islet within an island. Name the islet.

7 letters. The 3rd is the "t" from Fouquet.

Ortegia, Spring of Arethusa?

Yes, you have it.

This French painter, best known for his Rococo style, was a "premier peintre du Roi".

8,7

2nd letter of 2nd word is "O" from Ortegia

Francois Boucher?

Yes, D_T

D_T???

Clue: This 18th century mansion was allegedly built for a nun who was the mistress of Portugal's king. It is now a museum.

2 words, 1st word 7 letters, 2nd word 7 letters. The 5th letter of the 1st word is a "C" from Francois Boucher.

Hint: The king was Joao V and the nun was Madre Paula.

I give up! :-S
For most of the day I was reading up on Alfonso VI & Ines de Castro, but she wasn't a nun...
I couldn't find much on Joao V or Madre Paula except he built a big convent in Mafra and she was at the convent of Odivelas.

I hope someone else find the answer soon!

yk,

Now I feel bad. I didn't think it would be so difficult, sorry.

This should simplify things...The museum's name is Museu da Cidade.

Don't feel bad. It probably isn't difficult for others.

Palácio Pimenta?

Correct, You're Up!

All of this artist's work was bequeathed to his nation according to his will. There is also a prize named after him.

6,7,7,6

5th letter of 2 word is "O" from Palácio Pimenta

Here's a hint: The 2003 winner of his prize is a transvestite ceramist.

Joseph Mallord William Turner?

Correct!

For anyone who is interested, the last 2 clues I gave: Francois Boucher & Joseph Mallord William Turner are both exhibitions currently held at the Kimball Art Museum in Dallas, Texas.
http://www.kimbellart.org