Profile: Syria's top-secret Jamraya research centre
The scientific research centre in Jamraya was established during the 1980s, at a time when the Soviet Union was the main military ally of the Syrian regime.
It is located in the north-west of the city of Damascus behind Mount Qassioun.
The highest profile research centre in Syria, it is the workplace of many of the country's top scientists.
It is also one of Syria's most secretive institutions, with employees banned from communicating with any foreign agencies or foreigners especially during time of war and crisis, like now.
It is believed that Syria's most important research is carried out at the site, while weapons are developed and stored there.
The area is home to some of the most important strategic military bases in the country.
The Presidential Guard's 105th and 4th brigades - the latter headed by Maher al-Assad, the president's brother - are located around Jamraya.
Though it is situated on a hillside, it is believed that many of the regime's military reserves are in underground locations in the area.
It is close to the Lebanese border, which makes it easier to transfer weapons across.
But it is hard to get accurate information about what the centre contains, as personnel are closely watched and monitored to prevent any leaks.