Related Clues:

• Tour-book illustration
• Evaluation method
• Heavens-bearer of myth
• Midterm, maybe
• GPS offering
• It may be topographical
• Sightseeing aid
• Eye __
• Mythical burden bearer
• Mountain guide, perhaps
• Treasure-hunt aid
• Bit of lab work
• React to acid
• Mental workout
• Set off, as an alarm