Half-Blood Hill is one of the hills surrounding the valley where Camp Half-Blood is located. It is well known for being the place where Thalia gave her life to save Luke, Annabeth, and Grover and that's where her pine tree is (in fact, it was named "Half-Blood Hill" because Thalia gave her life there). After several automatons, including the bronze dragon, Thalia's tree successfully guarded the hill and kept monsters out. The Golden Fleece now protects the hill, since the tree no longer uses Thalia's spirit. Peleus, the dragon, guards the Golden Fleece. Mortals and monsters cannot go past the hill's magic borders, unless one of the campers, Chiron, or Mr. D allow them in. To mortals, Half-Blood Hill is a strawberry farm.