A charm of Yabe (now Yamato-cho) is its vast network of irrigation built over centuries to deliver water to its terraced paddies. A challenge was Shiraito Plateau, which was cut off from any waterway by deep ravines, so in 1854 Tsujyunkyo (通潤橋) was built both as a bridge and an aqueduct. Water passes from a canal on the north through three channels embedded in the bridge, driven by a slightly higher elevation on the northern inlet compared to the southern outlet. A problem of sediment buildup in the channels inspired a creative solution: drainage holes at the lowest point in the center of the bridge, plugged by wooden stoppers which are occasionally removed to flush the channels.
The bridge suffered damage in the quakes so was closed to remove the upper layer of rock to allow realignment and grouting of the aqueduct stones. Just ready to reopen in 2018, a retaining wall at its southern base collapsed due to a typhoon, so then that had to be rebuilt. Finally, after four years of restoration (and barring another natural disaster), it is set to reopen on April 19th. The sluices will be opened daily from 1:00 for 15 minutes.
While you’re there, visit nearby Gorogatki - a fabulous path winds down a sheer cliff to its base; there is also a suspension bridge. The entire area makes a wonderful day trip. Wear shoes suitable for hiking. - William