Check in was flexible. When I got lost, Nicolas was helpful finding the apartment (it is on the side of the street with the hotel with the flags). The apartment is up 5+ flights of stairs until you reach the top floor. It is a very cute apartment that included enough beds and towels. Unlike airbnbs that I've stayed in before, this apartment seemed like it was currently being lived in and left just for the weekend to Airbnb. It works for a weekend trip. The apartment is located close to the Strasbourg Saint Denis metro (4,8,9 lines). The neighborhood wasn't exactly the Marais. It was convenient, near cafes, grocery store, stores, and restaurants. Check out was simple and at 11am (which we didn't realize and left a little late).