Most workers at the ISAF headquarters at Kabul have never seen this stone plate which reminds on an Afghan soldier who fought against the British. The memorial was donated by ISAF in 2008. It carries an inscription in Arabic (Pashtu/Dari?) and English.
It quotes:

"'Not equal are the Companions of the fire and the Companions of the Heaven; it is the companions of the Heaven that will achieve felicity.' Chapter (59) sūrat l-ḥashr (The Gathering)"
"Shrine of the Mujahid matyred soldier who fought against the British invasion during Amanullah Khan era. Donated by ISAF 2008"

"'To Allah we belong and to Him is our return.' Chapter (2) sūrat l-baqarah (The Cow)"
The location is well covered from most views and a really save era. It is easy to find as in a military environment long searches and crawling on the ground might be considered suspicious. You don't have to get down to the ground to grap the petling but to reach out. It is not at the memorial but at the wall.
Many, many thanks to Clever Clogs who performed a maintenance on the cache, preventing me from travelling more than 5,000 km
.
Bring your own pen.