Where is the Ramban's tomb?

In 1267, Rabbi Moshe bar Nachman (the late Ramban) writes in a letter to his son who is in Spain:

"God bless you, my son Nachman, and see good in Jerusalem, and see sons for your sons, and as Abraham's messenger will be your messenger. In Jerusalem, the holy city, I am writing this book to you, because praise and thanks be to my God Yeshua I won and I came to peace (Jerusalem) on the ninth day of the moon of Elul. And I stood in peace until tomorrow On the Day of Atonement, on which I am inclined to go to Hebron, wake up the graves of our ancestors and carve a grave for me with the help of God, and whoever is privileged to see it in ruins will be privileged to see it in its building and repair, when the glory of the Shekinah returns to it."