The Colosseum is known to everyone. Today it is the most famous ancient monument in Rome. And maybe even the whole world. No wonder they are already beginning to call it one of the wonders of the world. Although it must be said that none of the ancient and medieval authors called the Colosseum a wonder of the world. And, in general, references to it in ancient primary sources are quite few. But, as the authors prove, the Colosseum is a fake. However, this is not a simple fake. It turns out that the famous Colosseum is a LATE COPY OF AN ANCIENT original. The authentic ancient Colosseum, which “ancient” authors wrote about, REALLY EXISTS. Its impressive ruins still stand today. But not in Rome, but in Istanbul. The second chapter of the book is devoted to the chronology of the construction of the famous mosques of Istanbul. The book does not require special knowledge and is intended for anyone interested in the use of mathematics to uncover the mysteries of our history.