If you were a Greek tourist in the 1st century BCE you would likely have had something in your hand that would be quite familiar here in the 21st century. A guide book. The most popular guide book of the Hellenic world listed seven wonders of the world that should be visited by any Greek traveler.
Of those seven wonders, six no longer exist. The Colossus of Rhodes, the Lighthouse of Alexandria, and the Mausoleum at Halicarnassus were lost to natural causes, the Temple of Artemis and Statue of Zues destroyed by human hands, and no one knows what happened to the Hanging Gardens. The remaining wonder is the Great Pyramid of Giza. This colossal Egyptian structure is so grand a work that even today, 4,500 years after its construction, it is still considered by some to be the most impressive civil engineering project in history, beating out feats like the Panama Canal, the Hoover Dam, and the Golden Gate Bridge.