“Bashi”, or “Hashi” means a bridge in Japanese, and “Nihon” is another name of Japan, so “Nihon-bashi” means the Japan bridge, which is also stipulated as the initial point of the national road grid in Japan.
You may understand why the bridge is the most famous in Japan. The bridge is located in the same named district in Chuou-ku Ward of Tokyo.
In order for you to reaching the bridge correctly, you had better using the words “Nihon-bashi bridge” if you ask Tokyoites how to get there.
Learn Japanese History
Learn Japanese Culture