Question: is the washington monument hollow?
Answer: The Washington Monument is a hollow Egyptian style stone obelisk with a 500-foot (152.4 m) tall column surmounted by a 55-foot (16.8 m) tall pyramidion. Its walls are 15 feet (4.6 m) thick at its base and 1 1⁄2 feet (0.46 m) thick at their top.