Dreams do come true

Once upon a time............

A son spends a semester in London, southwest on the Thames,
and of course, we want to visit him.
So we book a flight and a hotel and plan the days.
Then an idea pops into our minds.
The girls' hearts.
Paris.
So we book the train through the Chunnel and plan our days.
Then, where do we stay?
Working on where to stay  and how to get around under ground or above ground.

Any help with the City of Lights?
Need to book a hotel for 2 nights. Seems like a FB request that you see
all the time but I won't go there!