Very old!
 
Magnificent page from a late 15th - 16th century manuscript, verse from the Buddhist Sutra. Tibet.
written on one side in Tibetan. 
The prayers were written on pages made of mulberry leaf, the back seems to me to be vellum/leather.
Probably the main page or cover of a manuscript.
 
Dimensions: + - 50 cm x 15 cm x 0.2 cm