Sanganesan Skyline is a 5.1-kilometer scenic road that stretches from Higashihazu-cho in Nishio-City to Katahara Onsen, Gamagori-City, by the ridge of Mount Sangane. Driving it lets visitors experience the beautiful panoramic views of the Gamagori-City area, the Pacific Ocean, and Nagoya-City. If the sky is clear, it is even possible to spot Cape Irago at the extreme of Atsumi Peninsula or even Toba-City and its nearby islands, in the distant Mie Prefecture at the other side of Ise Bay! The road is also well-known for its perfect nighttime scenery and in the winter, from mid-October to mid-January, a surreal nightly illumination display decorates the area around the parking area at the peak of Mt. Sangane. The road's course is dotted by touristic attractions such as the recreation facility with hot spring bath installations, the Sangane Kannon and Hijima Kannon Temples, and the Junkoku-Nanashi Cemetery, a memorial for seven wartime heroes.

Over 70,000 hydrangea bushes bloom along the road from June to early July, hence it is also called the "Ajisai Line" ("Ajisai" is the Japanese word for hydrangeas), with another 10,000 around the peak's parking area. At the end of the road, 50,000 of those flowery plants awaits the visitors at Katahara Onsen's "Ajisai-no-Sato" (Home Place of the Hydrangeas) garden, with additional 10,000 at Honkoji Temple, known as the "Mikawa Area's Temple of Hydrangeas." Festivals celebrating the hydrangeas are held in various places of the region near the road during their blooming season.

Mikawawan Skyline (三河湾スカイライン) has its western entry point at about 4 kilometers north from the eastern end of Mt. Sangane Skyline, at the Fukozu-tennomae crossing of Route 248, in Kota-Town. Its course totals 17.6 kilometers until it gets to Toyooka-Town, in Kunizaka, Okazaki-City, where it meets Aichi Route 368, known as "Kunizaka Kaido" Road. Initially a toll road, it’s been converted to prefectural road, with the official name of Aichi Prefectural Road 525 Gamagori Loop Line.