The base area of The Pentagon, Washington DC, United States, is 100,000 m², if the courtyard is excluded.

To help compare sizes of different geographic regions, areas between 10 hectares (100,000 m²) and 100 hectares (1,000,000 m²) are listed below.

• Areas smaller than 0.1 km²
• 0.1 km² is equal to:
  • 1 E+5 m² or 100,000 m²
  • 10 hectares
  • 25 acres
  • 1.08 million square feet
  • the area of a square with side of 316.2 m
• 12 hectares – Base area of The Pentagon, USA
• 13 hectares - Place des Quinconces, Bordeaux
• 16.1874257 hectares - 40 acres - 1/16 section (US Survey block)
• 18 hectares - Jethou
• 19 hectares - Irish National Botanic Gardens
• 19 hectares - Liancourt Rocks (total area, all islets)
• 25 hectares - Tuileries Garden
• 28 hectares - Ponte Tresa (smallest municipality of Switzerland)
• 34 hectares - Disneyland (public areas)
• 35 hectares - Palace of the Parliament, Bucharest (floorspace)
• 36 hectares - Ryugyong Hotel in Pyongyang, North Korea (floorspace of largest unoccupied building)
• 40 hectares - Macroplaza, Monterrey
• 44 hectares - Vatican City (country ranked 234th by area)
• 44 hectares - Tiananmen Square, Beijing
• 62 hectares - The Pentagon (gross floor area)
• 72 hectares - Forbidden City, Beijing
• 90 hectares - Garden of the Versailles Palace [1]
• 99 hectares - Aalsmeer Flower Auction in Aalsmeer, Holland (floorspace)
• Areas larger than 1 km²