Cordoba, Spain (CNN) -- Muslims in Spain are campaigning to be allowed to worship alongside Christians in Cordoba Cathedral -- formerly the Great Mosque of Cordoba.
Today, at the original Cordoba mosque in Spain, there is no call to prayer, only the ringing of church bells. That's because the former mosque is now a working Catholic cathedral, performing a daily mass.
It's been a Cathedral since Spain's Christian monarchy conquered Cordoba in the 13th century and more than a million visitors walk through its doors every year.
Depictions of Jesus' crucifixion hang underneath the distinctive red-and-white arches of what was once the Muslim prayer hall. Cordoba's dazzling "mihrab" -- the sacred alcove from where Muslim prayer is lead -- still stands as a separate part of the site and is one of the main attractions for tourists.
In fact, the site remains significant for Muslims as a symbol of Islam's golden age of learning and religious tolerance. The Mosque of Cordoba was once famed for allowing both Christians and Muslims to pray together under the same roof.
Now, some Muslims are trying to repeat that history. Mansur Escudero, a Spanish convert to Islam, is leading the movement that is pushing for the right of Muslims to pray at the Cordoba Cathedral.
"I don't think it's important for Muslims. I think it's important for humankind," Escudero says. "We think this is a beautiful paradigm of tolerance, knowledge, culture. People of different religions living together."
Spain has more than a million Muslims, little more than two percent of the population. Most of that growth is made up of migrants from countries such as Morocco. But the southern European country has a significant community of Muslim converts inspired by its Islamic history.
In April, more than one hundred Muslim visitors staged a protest by unrolling their prayer rugs inside the site and beginning to pray. When security tried to remove them, the protest got violent and two were arrested.
According to Cordoba's Bishop, Demetrio Fernandes, this incident shows it is impossible to share a house of worship. It would be like sharing a wife between two husbands, he told CNN.
"Would they be happy to do the same in any of their mosques?" he asked. "Absolutely not. Because I understand their religious feeling and they have to understand ours as well. The religious feeling is the deepest one in the human heart, so it is not possible to share."
Bishop Fernandes points to the basilica of San Juan in Damascus as an example of a Christian site that has been converted into a mosque.
"We wouldn't think of asking for the Damascus mosque, because it belongs to the Muslims and for them it is an emblematic place.
"It is [the same] for [Christians] because the San Juan's basilica is very important to us, but we understand that history doesn't go back. It only goes forward. So, it doesn't make sense to ask for the Cordoba [cathedral] to convert it into a mosque, it doesn't make sense because history is irreversible," he said.
Escudero insists this is not about winning a victory for one religion or the other.
He said: "They pretend that we are trying to conquer the mosque again. That's not the intention at all. We want it to be a place where anyone -- whether Muslim, Christian or Jew -- can do his meditation or his internal way of worshipping, or praying or whatever he wants to call it."