Some places around the world have become must-sees for millions of tourists, but we rarely know what secrets they are hiding. The Roman Colosseum used to be nearly twice as large as it is today! Its architectural glory started to dim down in 217 when a fire struck the upper parapets and much of the building's interiors. The downfall continued with an earthquake, and a big part of the Colosseum's outer ring was damaged. What else happened to the Colosseum and other famous monuments of architecture worldwide? Let's find out!