The town of Mine in central Yamaguchi is known as the fossil capital of Japan. Dominated now by cement production the area is geologically quite interesting.
It was the site of one of the first copper mines in Japan, in Meiji coal was mined here, and also marble. Now it is known for Akiyoshidai and Akiyoshido, the largest karst and limestone cavern in Japan.
There are two museums, the Fossil Museum, and the local History & Folklore Museum, that have extensive displays of fossils, and the main street has a series of small sculptures based on fossils. It is even possible, for the whopping fee of 100 yen, to look for your own fossils at a local site though you need to bring your own hammers and safety glasses.
Not surprising then that the towns manholes feature ammonites.....