@sunnylowkey, have a wonderful time!

I've never been to Madrid, but have visited Paris, Barcelona, and Lisbon. All great cities! Paris and Lisbon have a special place in my heart.

I had been to Paris a few times before, but the last time I went was during the height of the covid pandemic. I finally went to the Louvre. It was a unique experience seeing that wonderful museum. Almost no one was there because of the pandemic. At one point, my husband and I were the only people in the room that had Da Vinci's painting of the Mona Lisa, and even other rooms. I imagine the museum will be crowded when you go. Maybe consider buying the tickets online, ahead of time, to avoid long lines.

My favorite thing in Barcelona was the Joan Miro museum/foundation. I love Miro's art (own two prints), plus it is located on a high hill with a spectacular view of the sea and a lovely large park around it. If interested, see Joan Miro Collection | Fundacio Joan Miro We had to take a taxi to/from there. Again, good to book tickets ahead of time.