Be in for a surprise!
We rented Onder's apartment for a month. All the reviews looked great, and he was listed as a 'superhost' so we expected the accommodation to be of an adequate standard at least. We specifically chose it for its lovely garden , as described in the listing. My wife and I have stayed at many Airbnbs, and have had great, good and at least, adequate accommodation. We also live in India so we are not particularly sensitive when it comes to accommodations as India can offer up some of the best as well as the worst perhaps in all the world. Nothing however prepared us for this particular scenario.
When we entered the apartment there was a smell which we presumed was mold and would dissipate once it was aired out and occupied. We assumed it had been closed up for weeks. Since there is no ventilation other than from the two sliding glass doors into the garden, we opened those. That is when we realized that the odor we were smelling was mold combined with the powerful stench of cat spray/urine. The garden is shared with stray cats, with at least 10-12 being fed by the hosts daily. There was a large bag of food with the instructions to keep the cats fed, and also a jar with "tips for the cats" written on it, for financial contributions towards cat food. Feeding the cats was not mentioned anywhere in the listing but as we love animals, we had no problem with it other than being asked for contributions.
The listing suggested we relax in the garden on the reclining chair. Unfortunately it is also utilized by the numerous tom cats to mark their territory, saturating it in cat urine and rendering it unusable.

We did try and work with the hosts to at least make our stay bearable. I cleaned the garden area on my own once and another time with the host's wife. We washed the numerous areas used by the toms. The result was a somewhat better atmosphere for about an hour, maximum. We also went along with the hosts pleas to give them some time to sort the problem, which became clear was impossible. While they did get some of the toms neutered, after surprisingly asking us to split the costs which we refused, the stench was so ingrained that without professional help it would take longer than our stay to abate. Also, due to their daily feeding policy, the neutered toms would quickly be replaced by unneutered ones.
To amplify the problem the screens on the doors were covered in tom cat spray. Our options were keep the doors closed, leaving us with no ventilation whatsoever(there are no windows in the apartment and regardless the stench permeates right through the doors) or open the doors and have the toms spray on the screen causing an even more unbearable stench. Realize, this odor was not only in the living room, but in the bedroom which also has sliding glass doors which were sprayed regularly with cat urine. We even have photographs of one of the cats actually spraying the bedroom screen door! That's how regularly the spraying took place: multiple times per day, by multiple cats.
We suggested they remove the reclining chair from the garden as it was filthy, soaked with urine and being repeatedly sprayed on. Onder agreed to immediately remove the chair but didn't get around to it for three days and when he did he didn't even bother to clean up the garden debris and dirt from underneath, which was also soaked in cat spray. This was getting to the point where our very patience with Onder and the situation was coming to an end.
A day or two later after some light overnight rain, the humidity caused the stench to increase, now permeating 90% of the living space. We notified Air BnB, packed our bags and left, with two and a half weeks left on our reservation and no guarantee of any reimbursement. This should stress to anybody reading, how severe the situation was. Before leaving we made sure the apartment was clean and tidy. We have always been easy going and responsible guests and we were very distressed by the entire situation and did not want any further conflict.
Our biggest regret, was unpacking our bags in the first place and then staying a full 11 unbearable nights in an effort to give the host and the apartment a chance. In retrospect we feel very foolish.
I hope Onder can get this property up to at least a tolerable standard, and it beggars belief that he has somehow managed to get good reviews with such a blatantly obvious problem. He assured us that we were the only guests to ever complain but at the same time his wife told me they faced the same issue when they themselves lived in the flat, so I am not convinced. I also want to add that the hosts were perfectly nice people but their listing at present is not habitable and they need to put in the work required to make it so, without expecting their guests to help either financially or physically. It is not the responsibility of the guests. My heart goes out to the people who have already booked this apartment.