Michaella McCollum Connolly and Melissa Reid will be locked up in the Virgen de Fatima jail – which houses some of Peru's most notorious killers – while they await a trial date.
The pair face up to two years in the prison, which is one hour north of Lima.
They are being held on drugs charges after being stopped at Jorge Chavez Airport on August 6 while trying to board a flight for Madrid with 11kg of cocaine worth £1.5m in their bags.
Co Tyrone woman Ms McCollum Connolly was yesterday led out of the Palace of Justice in the port city of Callao with her travelling companion, Glaswegian Melissa Reid.
The pair, both 20, claim to have been kidnapped and forced into carrying the drug by gangsters.
The prison system in Peru is operating at 200% over capacity, and prisoners often sleep in packed dormitories or in corridors.
Violence and bullying are rife, food is extremely poor and clean water has to be bought.
Almost all foreigners incarcerated in Peru are held in either Fatima de Virgen or the Santa Monica prison for women.
The pair were remanded in custody on Wednesday after a hearing in Callao. Judge Dilo Huaman said he was turning them over to the prison service so it could decide which jail to send them to.
Officials said the two had confessed to investigators that they knew there were drugs in their suitcases. However, they insist they were forced to carry the cocaine by an armed gang.
Ms McCollum Connolly had said moments after her arrest that she had no idea she was carrying drugs in her luggage.
A spokesman for the court said: "Both foreign citizens, although they claimed they had received threats to make them take the drugs, admitted they knew there were drugs in their luggage and didn't warn the authorities.
"For that reason and for others they were remanded in custody. Under article 296 of our penal code, both women could receive a prison sentence of between eight and 15 years."
Dungannon woman McCollum Connolly is being presented as a glamorous drugs mule in the Peruvian media.
She is proving front page news in the local tabloid press, which described the Irish girl who "looks like the singer Amy Winehouse". After their court appearance, the local El Trome newspaper focused entirely on Michaella.
The two women are are repeatedly referred to as "burriers" – or mules. However, the girls' story of being forced to carry the drugs by an armed gang has gained massive attention.