In 1971, Iran threw a party. A big one.
It took 10 years to plan and lasted five days. The Guinness Book of World Records recorded it as the most “well-attended” international gathering in history. More than 600 foreign dignitaries, including some 65 heads of state, abandoned their presidential palaces and braved the Iranian desert—on sand dunes on the outskirts of Persepolis, capital of the ancient Persian Empire.