It takes approximately 3 hours to get from my town of Esch to Paris, and the journey covers 340 miles round trip!
I've done a few day trips since arriving in Luxembourg. It was about 75 miles to Metz, France; 50 miles to and from Trier, Germany; and 230 miles to and from Brussels. The trip to and from Paris was also 340 miles, making my grand total 695 miles traveled since arriving in Luxembourg!
I mostly used the Paris metro, although I got plenty of steps in walking from one neighborhood to another as well.
My favorite place in Paris was definitely the Notre Dame Cathedral! On my previous visits to Paris, it was still closed for renovations after a fire destroyed part of it in 2019. Getting to finally see the famed Cathedral in person was a dream come true!