'Syria welcomes you' proclaims the sign as you cross the border from Turkey. It's an ironic throwback to the old days, when this was a country that really did welcome outsiders. Today's Syria is a very unwelcoming place - a place that people are scrambling to escape in their tens of thousands each week.
The UN has described the Syrian emergency as the worst refugee crisis since the Rwandan genocide. But sadly, as with Rwanda, I have seen for myself that there is no UN presence in the places inside Syria where it is needed most. And the international community seems powerless to bring an end to the suffering.
I wish the G8 leaders had been in Syria with me when I visited at the weekend. Then they would have witnessed the anguish and despair on people's faces, a terrible indictment of the woefully inadequate International response to this conflict.
Fresh diplomatic impetus is urgently needed to establish 'humanitarian corridors' that will allow for more and better coordinated aid, to strengthen the international presence inside Syria and to bring about the peace talks that were promised in May - something Islamic Relief is joining with other agencies in petitioning Presidents Obama and Putin about.
The numbers involved in this crisis are shocking. Around 100,000 Syrians dead, between two and three million refugees, 6.8 million in need of urgent assistance. The death toll is growing by 5,000 a month, and the number of refugees by 6,000 a day.
One of the first things I witnessed inside Syria was hundreds of exhausted people streaming towards the border. They were carrying what little they could of their possessions, determined to seek refuge wherever they could find it.
Islamic Relief's staff have to make frequent cross-border deliveries into Syria because it is too unsafe to establish a large base inside the country - one of the consequences of the lack of humanitarian corridors to protect aid operations.
During my visit I saw a makeshift hospital stretched to breaking point and one of the new camps that are springing up almost every week as aid agencies struggle to keep up with the huge numbers of people being displaced by the widening conflict. Aid is getting through, but there simply isn't enough food and water to sustain everyone in the 40-degree heat.
The camp I visited had been set up in the olive groves just ten days before we arrived but it was already home to over a thousand people, including 600 children. As we distributed Ramadan food packs, among the first recipients were Ahmed Abdul Karim and his amputee daughter. He said they had lost loved ones from three generations of their family, and showed us a framed picture of his late wife, daughter, son and four grandchildren - all casualties of this brutal war.
I was almost speechless. What words of comfort can you offer to a bereaved elderly man like Abdul Karim breaking down with grief, or to a weeping father whose son has just been declared 'dead on arrival' at the hospital with a bullet in his head?
I also visited the Bab al Hawa hospital, which in happier times was a restaurant. Now it is full to overflowing with casualties of the conflict and has treated 10,000 people in just six months. It is one of 30 Syrian field hospitals and 60 clinics supplied and supported by Islamic Relief.
On ward after ward I saw people with sickening wounds and missing limbs, all being treated in very basic conditions. Fifteen-year-old Mustafa Ahmed screamed in pain as the doctor removed his soiled bandage to reveal a gaping wound, open to the bone. Here was an innocent schoolboy in a makeshift ward, his leg severely damaged by shrapnel from a shell, uncertain whether he will ever walk again.
I urge you to give generously to Islamic Relief's life-saving work, but we must also redouble our efforts to end this terrible conflict. That means calling all sides to come to the negotiating table, because ultimately there can be no humanitarian solution to a political problem. Peace talks are the only hope of providing real respite to the long-suffering Syrian people.