This structure is names for its resemblance to a “turkish chair” and is found as a saddle-shaped depression on the sphenoid bone. The indentation (or the seat) is where the pituitary gland is located.
To find the sella turcica, locate the sphenoid bone from the inside of the skull. The sphenoid bone is named for its shape, which resembles a butterfly. A portion of the sphenoid bone can be seen within the eye socket and in front of the temporal bone as shown on this animation.

https://commons.wikimedia.org/wiki/File:Sphenoid_bone_-_animation.gif