The signs, which measure 55 centimeters high and 10 cm wide, describe how many meters above sea level the area is in Japanese, English, Chinese and Korean.
Yokohama, the capital of Kanagawa Prefecture, has a Chinatown and many tourist attractions along the coast. It plans to serve foreign residents and tourists by installing the signs on light poles and curved mirrors.
The municipal government plans to install about 7,700 such signs by the end of March in areas that may be flooded in a tsunami, as well as areas that are less than 10 meters above sea level.
The local government decided on the measure in the wake of the March quake and tsunami in northeastern Japan.
The Yokohama city government has begun installing signs Thursday at its coastal areas showing the elevation in four languages to help foreigners evacuate in case of a tsunami.
