The 262-bed hotel had been regarded as a symbol of Western opulence until the Islamic State militants seized the city in June, 2014.
However, pictures published online claim the five-star hotel is again welcoming guests with open arms.
The pictures show refurbished rooms, a well-kept garden, freshly polished marble floors, signs in the English language and… strange black ISIL flags fluttering in the wind above all these splendors.
Those who violate the Islamic rules are at risk of being decapitated, while ISIL's infamous female police al-Khansaa will keep an eye on guests to ensure observance of Islamic values and practices.
However, looking at the pictures of lavish interiors and brightly colored balloons floating in the sky, one may forget that the hotel is located in one of the most dangerous cities in the world.
The ISIL initiative has immediately sparked a lively debate in social media.
"ISIS brand of puritanical Islam isn't comfortable with modern concepts like coexistence and representation, but just fine with luxury spas," wrote one commentator on Twitter.
"Mosul looks like being a fun holiday destination this summer: ISIS [ISIL] have just opened a hotel," noted another with unconcealed sarcasm.
ISIS brand of puritanical Islam isn't comfortable with modern concepts like coexistence and representation, but just fine with luxury spas.— Kareem Shaheen (@kshaheen) 6 мая 2015
@kshaheen against the West!! (except for Twitter, food, entertainment, mobile phone tech, vehicles, weapons, transport, etc)— Shami Witless (@Shami_Witless) 6 мая 2015
I didn't know they had luxury hotels during the Prophet's time. Meet the luxury hotel/spa ISIS opened in Mosul: http://t.co/BhfIkwwiCj— Kareem Shaheen (@kshaheen) 6 мая 2015