A study by the Chamber of Commerce of Monza and Brianza, a small province near Milan, Italy has estimated that Paris’ most iconic building is worth €434 billion – about one fifth of France’s GDP.
Estimated values of two other emblematic European sites include Rome’s Colosseum (€91 billion) and Barcelona’s Sagrada Familia cathedral (€90 billion). The Tower of London was valued at €70.5 billion.
The value of each monument is not based on the material worth, but on their image, branding, and attractiveness to visitors. The figures were gathered from Eurostrat and Istat (European statistics bodies) and from the Urban Audit, a collection of comparable statistics and indicators for European cities.