Estelle et Erwan's apartment is certainly the place to be after a busy day out and about.
The spa downstairs is sure to give you some relaxing moments when you come back home after a long day venturing the streets of the city of lights. Just bear in mind that you're in Paris and places might be smaller than you might be used to back home. However, you will be surprised once you come in and see what's been waiting for you.
The only thing to bear in mind is the stair to the spa. It might be something to consider if you have problems in your back, knees or hips.