Hello how may I help you? What's the longest thing in the world? I'm sorry, can you be more specific? You know, like the longest thing. Like the great wall of China maybe? Or is there something longer? Do you mean the longest man-made structure? I guess so. The Great Wall of China is the longest man made structure How long is it? It is 200 kilometers long Interesting. Well, thanks for your time bot. You are welcome