Related Clues:

• Hollow
• Like some lenses
• Curving inward
• Inverted
• Hollowed out and curved
• Like the inside of a sphere
• Like band shells
• Curved and hollow
• Many on guard in hollow
• Depressed kid goes to Aladdin's magic place
• Curving inwards
• Shaped like the inside of a sphere
• Inward-curving
• Indented
• Curved inwards