Iraqi forces have captured the Mosque of the Prophet Younis, or Jonah, after driving Islamic State group militants from a new neighbourhood in eastern Mosul, a spokesman said.
The mosque was among dozens of historical and heritage sites destroyed by IS militants after their June 2014 onslaught, forcing Iraqi security forces to withdraw and seizing areas in northern and western Iraq.
The site is believed to be the burial place of the prophet Jonah, who was swallowed by a whale in stories from both the Bible and the Koran.
It was built on an archaeological site dating back to the 8th century BC and attracted religious pilgrims from multiple faiths around the world.
Special forces spokesman Sabah al-Numan told The Associated Press that security forces found only the fences alongside the ruins.
Meanwhile, the UN said in a statement issued late on Monday that the massive Iraqi military operation to retake the city of Mosul from IS has left more than 148,000 people homeless.
Nearly 12,500 people were forced to flee their homes just over the past week, the UN said.
The statement also said that the fighting over Iraq's second-largest city continues to inflict relatively high civilian casualties, with more than 1,500 wounded taken to hospitals in the nearby city of Irbil for trauma care.
IS fighters have repeatedly targeted civilians trying to flee neighbourhoods still under militant control.
More than a million people were estimated to still be living in Mosul in October, when Iraqi forces launched the operation to retake the country's second largest city from IS.