The singer has performed a concert in the Kurdish-controlled part of Syria after sneaking across the border.
The British star, whose second album Mind Body and Soul reached number one in the UK charts in 2004, posted on her Instagram feed that she was "glad nothing bad happened" as she crossed over.
It is understood she performed to 70 people in Derika, in the very far northeastern corner of Syria.
The border she crossed is not known, but northeast Syria is surrounded by Iraq and Turkey.
She has said she aims to visit every country on the planet on her Total World Tour.
The Mail on Sunday has reported that she was accompanied by Paul Conroy, the war photographer who was with Sunday Times reporter Marie Colvin when she was killed in the Syrian city of Homs.
Stone is a friend of Mr Conroy, who is understood to have been travelling to Syria for the first time since Colvin died.
Stone said on Instagram: "We made it into #syria #kurdistan it was a little scary crossing the border as of course we have absolutely no idea what might transpire, we just have to trust the people on the ground that are advising us and looking after us.
"This was the beginning , it was cold and wet but also so nice to meet such welcoming kind people .
"#syria deserves not to be ignored #kurdistan deserves not to be ignored . There is a lot of hurt here coming from all sorts of different directions.
"I heard that Isis surrendered yesterday but that doesn't mean it's all over for the Syrian people or the Kurdish people, it is so complicated, a story I'm not in a position to tell you but all I can say is that I have learnt a lot from my short time there and I hope that peace will come to every one on all sides soon."
She added on a video she posted: "We did the crossing. We're in Syria. It's bloody cold. I've got a blanket from Paul's room. I'm just going to warm myself up and get used to my new room which is actually really cool. I know it's freezing but I'm just so glad that I'm here.
"I'm so glad that... nothing bad happened."
At least one person posting on her feed referred to her use of the term Kurdistan - a country which under current international agreements does not exist - suggesting she received some comments in reaction.
Turkey regards many of the Kurds fighting Islamic State in Syria as terrorists because it views them as being linked to the PKK, the terror group which has long fought for an independent Kurdish state in Turkey.
Derika, which is also called Al Malikiyah in Arabic, is the meeting place of the Syrian Democratic Council, the political wing of the Kurdish-led Syrian Democratic Forces (SDF).
The SDF is currently engaged in a "decisive battle" with Islamic State further south in Deir ez Zor province. IS fighters have not yet, as Stone was told, surrendered.
Derika was captured from Syrian forces in the early months of the civil war, according to reports.
It contains a mixture of Muslim Kurds, Christian Assyrians, Christian Armenians and Arabs, according to the 2004 census.