Upon arrival at Peter and Terri's Airbnb unit, we were surprised that it was a basement apartment. We parked in the gated parking area behind the building and carried our luggage down rather steep stairs to the rear entrance of the unit. The concrete walkway from the stairs to the rear door was covered with slime and there was puddle at the door. The rear door entered into one of the bedrooms resulting in tracking wet/dirty shoes through the bedroom into the living area. After unpacking, we determined that the kitchen sink was stopped up and there was standing water in the disposal. The dishwasher was not installed properly and we could only open the dishwasher door 1/2 way. The unit was very damp and we asked the host for a dehumidifier. The following day, the host fixed the sink and said that he was unable to find a dehumidifier. Also, the ceiling over one of the bath tubs was dripping water and there was black mold on the ceiling and around the tub. There was evidence of black mold on the ceiling in the 2nd bath tub as well, which appeared to have covered with Kilns or some other coverup paint primer. The mold was giving off a strong odor and caused my daughter to start a persistent cough and my wife to experience problems with her asthma. After staying 2 nights in Peter and Terri's unit of the 8 night reservation, (by mutual agreement with the hosts), we moved to a hotel for the remainder of our vacation. We were only refunded approximately 1/2 of what we had prepaid for our reservation. Peter later notified us that the source of the mold and dripping ceiling in the their Airbnb unit was the result their upstairs tenants splashing water from their bath tub and not wiping the water up.