The Washington Monument: America's Tallest Stone Obelisk

The Washington Monument is a white marble obelisk in Washington, D.C., honoring the first U.S. president.

Key Specifications

• Height: 555 feet (169 m) — world's tallest stone structure
• Base: Square, 55 feet (17 m) per side
• Exterior: White marble from Maryland and Virginia
• Apex: Aluminum pyramidion (originally served as lightning rod)
• Observation Deck: At 500 feet (152 m), accessible by elevator
• Windows: Small openings near the top for city views

Construction spanned 1848–1884, interrupted by funding issues and the Civil War. The color change visible at ~150 feet marks the pause between marble sources.