Here is location of oldest basketball court

https://www.sortiraparis.com/en/news/in-paris/articles/308078-adopt-a-blade-from-paris-oldest-basketball-court-to-help-renovate-it#:~:text=In%20the%209th%20arrondissement%2C%20at,oldest%20basketball%20court%20in%20Paris!

I second the recommendation for bike tours. My teen sons and I have done bike tours in several cities, and we did two different tours in Paris. Great fun.

We also did a baking class, which we enjoyed.

I thought the VR experience of Notre-Dame was pretty cool. (Younger son had to stop partway through because it was making him sick.) (Note there are two locations -- right near Notre-Dame and out at La Défense.)

https://www.eternellenotredame.com/en/

Sidestepping the feces on the sidewalk.

Basketball fan per chance? See oldest basketball court in the world.

Salsa clubs 100%

Not sure if this is unusual but I liked Château de Chambord

Sewer tour. Was surprisingly fun and interesting

Download Flash Invaders and see how many you can find! Perfect for an 18yo.

Try Atlas Obscura - we've found all kinds of off the beaten path things to do in other countries and in our own backyard

We did a fun food tour

Musée de l'Orangerie

We liked taking a perfume making class

Kids like the Catacombs and biking tours

Not so unusual but i had a good time at the le cordon blue cookery class
I also liked visiting the urban farms but that might not be in season now

We're going to be in Paris for a couple of days soon. We've been there before and covered a lot of the tourist highlights already, so it would be nice to do something a little different or see something that might not make it to the usual top 10 lists. Any suggestions? We'll be with our 18 year old, fwiw. Also, any restaurant recommendations that might have a lot of options for vegetarians?

Thank you!