In science fiction and speculative (or exploratory) engineering, a megastructure is an enormous self-supporting artificial construct.

Existing Structures

• The Great Wall of China
• Berjaya Times Square
• Boeing Everett Plant
• Taipei 101
• Petronas Towers

Famous Structures (cf.)

• Eiffel Tower
• Big Ben
• Sydney Opera House
• Statue of Liberty
• Great Pyramid

Natural Structures

• Mount Everest
• Mount Fuji

Proposed structures

• Shimizu Mega-City Pyramid
• X-Seed 4000
• Sky City 1000
• The Illinois
• Burj Dubai

Theoretical Structures

Planetary Surface

• Arcology
• Disc Cities

Satellite-scale Structures

• O'Neil Halo
• Skyhook

Planetary-scale Structures

• Jupiter Brain
• Globus Cassus

Stellar Engineering

Fictitious Megastructures

• Death Star
• Star Forge
• Borg Transwarp Hub/Unicomplex