Unfortunately we received not a prompt answer, so that we had to stay in the apartment despite of all. We were in 4 people: one ancient and 2 obese people full of luggage since we have been travelling in Europe for 2 weeks.
We had to climb more than 100 stair steps, carrying such bags to the 4th floor. Just above the 2nd floor we found a special lift (for the luggage).
We are very upset with Booking since such information was not available in the reservation site, and we Will certainly consider that in the future!
We arrived at night and in the surroundings there is nothing open, no supermarket, no restaurants, no parking in the building and not near the apartment, anyway it was a very bad experience, I do not tell any friends.