"border temple" (i.e. [mtha'] yang 'dul gyi lha khang) in the upper reaches of the Brahmaputra
"[...] Pra-dun-rtse (8) west of Sa-dga' rDzong in the mNga'-ris province of western Tibet, a temple, where I have established elsewhere a branch of the old royal dynasty came to settle." Aris 1979 (p. 23)
on a black tortoise, affiliated branch gnyen gsal gyi lha khang /, see lde'u chos 'byung [1987] (p. 116.8-10): byang du sbal pa nag po'i mchu stengs su spra dun tse/ de'i 'phyong du gnyen gsal gyi lha khang bzhengs so /, also Sørensen & Hazod 2005 (p. 186)