Nanatsugama Sea Cave Coastal Trail

The Nanatsugama Sea Cave Coastal Trail follows the clifftops above the Genkai Sea coastline at Yobuko, part of Karatsu, Saga, tracing the basalt cliffs that hold the seven wave-carved caves (Nanatsugama) the trail is named for. The trailhead is reached by Showa Bus from JR Karatsu Station toward Yobuko, a 30-minute ride, followed by a 10-minute walk from the Yobuko stop to the clifftop path near the sightseeing boat dock; free public parking is also available near the dock for those arriving by car. The out-and-back route covers about 2.5 km round trip and takes 1 to 1.5 hours, with gentle undulation and under 60 m of elevation change, making it accessible to most fitness levels. The path itself is a mix of paved promenade near the boat dock and a dirt-and-grass clifftop track further along, with no shade for most of its length and constant exposure to sea wind. Basalt rock near the cave overlooks becomes slippery when wet, so care is needed at the viewpoints closest to the cliff edge. Key landmarks include the main overlook above the largest cave, where sightseeing boats can be seen entering the caverns below at high tide, and the Genkai Quasi-National Park boundary marker partway along the route. There are no water sources or shelters on the trail; the nearest facilities are at the Yobuko boat dock and the adjacent morning market (asaichi). The trail is best used as a there-and-back walk, with the main overlook serving as a natural turnaround point for visitors not continuing the full route.