The Congress Hotel Weimar by Mercure is appreciated for its beautiful indoor pool and sauna, which many guests have found to be great amenities during their stay. Some guests have noted that the pool is a good option for kids on rainy days. While some reviews complained that the pool was too cold or not heated, others enjoyed the nice size and cleanliness of the pool. Despite some negative feedback, the inclusion of a pool was a deciding factor for some guests when booking their stay. Overall, the pool is a welcomed addition to the hotel's facilities.