Orthanc is a fictional tower from J.R.R. Tolkien's Middle-earth, specifically featured in the story of The Lord of the Rings. It is located in the realm of Isengard, which is surrounded by a circular wall and is home to the wizard Saruman. The tower is made of black stone and stands tall, symbolizing Saruman's power and ambition. The tower serves as a strategic location for Saruman, who uses it to conduct his experiments and forge alliances with dark forces. Orthanc is also significant for its palantír, a seeing-stone that allows communication and vision across great distances, further enhancing Saruman's influence.