The brain is entirely located inside the cranium, which is the bony structure that protects it. There are no parts of the brain that are located outside of the cranium.

Perhaps you're thinking about the spinal cord, which is a long, thin bundle of nerves that extends from the brain down the back. The spinal cord is housed within the vertebral column, which is a series of bones that protects it.

Let me know if you have any more questions!