The term 'Tree Sacred to Druids' refers to two trees in particular: the YEW and the OAK. The YEW is an evergreen tree that is native to Europe, North Africa, and parts of Asia. It has been used for centuries in religious ceremonies and is associated with death and rebirth. The OAK is a deciduous tree that is native to Europe, North America, and parts of Asia. It is a symbol of strength and endurance and has been used in many religious ceremonies. Both of these trees have been sacred to Druids for centuries and are still revered today.