It comes as US President Barack Obama renewed his call for the closure of the facility during his final State of the Union address.
January 2016 marks 14 years since the opening of the United States detention centre in Guantanamo Bay, Cuba.
But it's a milestone many would prefer had never been reached.
The camp was established following the September 11, 2001, attacks on the US to hold, interrogate and prosecute alleged enemy combatants in the Bush administration's so-called War on Terror that ensued.
It is located in a place where, it's said, US and international law do not apply.
Over the years, reports of torture and severe abuse have emerged, leading international groups to call for the facility to be shut down.
Among those calling for the closure of Guantanamo Bay are human rights experts from the United Nations, who have written an open letter to the US government.
Monica Pinto is the UN Special Rapporteur on independence of the judiciary, and one of the signatories to the letter.
She told UN Radio the group wants all Guantanamo detainees to have access to justice.
"We're trying to ask the government of the United States to promptly close the Guantanamo Bay facility, to end the arbitrary detention of all the people who are detainees in this facility and at the same time, either to release them to their home countries, or to transfer them to some detention facilities in the US territory and of course to ask for them to be transferred to a judge to be the object of a judicial process with the due guarantees of a free and fair trial."
The advocacy group Amnesty International says of the nearly 800 men taken to Guantanamo Bay, only seven have been convicted.
Amnesty says the men who have faced trial went before a military commission that failed to meet fair-trial standards.
Many have been released after years of detention without charge or trial.
The force-feeding of detainees on hunger strike has drawn international attention to allegations of torture and ill-treatment of prisoners.
Ms Pinto says further investigations into the claims of human rights violations must be carried out.
"We are also calling on the government of the US to establish an independent oversight mechanism so as to receive the complaints on torture, ill treatment and other different species of treatment that the detainees have suffered. And to award all of them the right to an effective remedy with a judge."
When Barack Obama came to office in 2009, one of the first initiatives he announced was a plan to close Guantanamo Bay.
However, his attempts to achieve this have been repeatedly blocked by the US Congress.
Mr Obama says he hasn't ruled out using his executive authority to intervene.
Speaking during his final State of the Union Address, Mr Obama again vowed to ensure the centre was closed before he leaves office.
"I will keep working to shut down at Guantanamo. It is expensive, it is unnecessary, and it only serves as a recruitment brochure for our enemies. There's a better way. And that's why we need to reject any politics, any politics that targets people because of race or religion. This is not a matter of political correctness. It is a matter of political correctness. It is a matter of understanding what makes us strong. The world respects us not just for our arsenal. It respects us for our diversity. And our openness, and the way we respect every faith."
Monica Pinto says Mr Obama needs to outline a plan to close down the facility.
"We don't have doubt about his commitment to try to close the Guantanamo Bay facility. What we think is that even though his government has been either taking measures or pushing the report that was published by the senate in which it is clear that torture and ill-treatment had been practiced with the detainees in Guantanamo, what we see is that in fact there should be some major political obstacles that have been crucial for the president to move forward in order to close the facility."
Currently, Guantanamo Bay holds approximately 100 detainees.
Amnesty International says almost half of the men have long been cleared for release, but are still being detained.
Shaker Aamer is a British resident and Saudi citizen who was freed in October 2015 after being held at the facility without charge for more than 13 years.
He was apparently captured in Afghanistan in 2001, where he claims to have been working for a Saudi charity organisation.
Mr Aamer has told the news service, Russia-Today, he and other fellow detainees were imprisoned for over a decade because the US could not prove any of the war crimes allegations made against them.
"That place has to be closed. Not next year, not next month, not next week. No, it has to be closed today. It has to be closed because a place like that shouldn't exist in our time. I mean, how can you justify keeping people for 14 years and telling the world that you cannot prosecute them, neither you cannot let them go because they are too dangerous. I think it's a true statement, I think it is a true statement, these people are too dangerous to let go and it's too hard to prosecute, actually impossible to prosecute. But why? Why after 14 years it's too hard to prosecute these people? Because it will show the failure of the intelligence service, the CIA and all the other services that have been in this case for all these years, that they couldn't prove that these brothers did anything wrong."
