We recently stayed at the Hotel Atrium, but our experience was severely marred by a serious sewage issue. The manager informed us that the hotel's drainage system pushes back Budapest's sewer smell into the bathrooms, exacerbated by a lack of ventilation in the toilets.
Due to the overwhelming odor, we were forced to keep the bathroom door locked throughout the night, as no alternative rooms were available. The next morning, the housekeeping staff member who opened the door was nearly overcome by the smell.
The hotel's attempt to mitigate the issue with chemical cleaning, multiple flushes, and air fresheners provided only temporary relief. Despite providing us with a freshener spray, the smell persisted. It wasn't until we requested a room change that the hotel accommodated us, as we were unable to sleep due to the unbearable odor.
Unfortunately, I strongly advise against staying at this hotel due to its severe sewage issues. Our experience was undoubtedly the worst I've encountered in any hotel