Kiessa Monastery
From Memory Alpha, the free Star Trek reference.
Kiessa Monastery is a religious retreat on the planet Bajor.
During the Cardassian Occupation of Bajor, the monastery was destroyed by four hundred Cardassian soldiers. Seventeen unarmed monks were also killed.
A young Tekeny Ghemor was among the Cardassian soldiers present at the massacre. (DS9: "Ties of Blood and Water")
