https:// medium.com/@EricTerman/why-is-genie-oil-troubleshooting-north-korea-ffe393be69fe
"This network of tunnels is a real spider's web," said a Syrian army official who escorted journalists on a visit Monday to areas of the Damascus suburb recaptured from the rebels.
http:// www.dailymail.co.uk/wires/afp/article-5570679/Rebels-leave-labyrinth-tunnels-Syrias-Ghouta.html
In Eastern Ghouta, Syrian rebels left behind an underground labyrinth, fitted with hospitals and military headquarters.
https:// treasurereading.com/beneath-the-ruins-of-syrias-ghouta-rebels-left-behind-a-labyrinth-of-tunnels/
https:// www.npr.org/2018/04/08/600625677/syria-denies-report-of-poison-gas-attack-in-eastern-ghouta
https:// www.aljazeera.com/news/2018/02/syria-chemical-attack-suspected-eastern-ghouta-siege-180226142923247.html