The Izu Skyline is a ridge road, and that one fact explains why motorcyclists have loved it for decades. It runs for tens of kilometres along the high spine of the Izu Peninsula, a toll road that keeps to the crest rather than diving into valleys, so the view changes constantly: on one side the Pacific and Sagami Bay, on the other the deep green slopes toward Suruga Bay, and, on a clear day, the near-perfect cone of Mount Fuji across the water.
The riding is fluent rather than frantic. The road links long curves with gentle rises and falls, the surface is generally good, and traffic is lighter than on the roads below, though weekends bring groups of cars and bikes. Limits are enforced and the road is monitored, so the pleasure is in rhythm and in the views. Morning is usually the best time for Fuji, since haze builds later in the day, while cold, clear winter days give the sharpest outline but also bring a chance of ice at height.
The mountains here were built by volcanic activity, as the Izu Peninsula is the northern tip of the Izu-Bonin arc, which has been colliding with the main island of Honshu for millions of years. That is why the peninsula has so many hot springs and why its slopes are covered in dense forest, with bamboo, cedar and broadleaf trees. Mist drifts in easily, and the ridge can be in cloud while the coast below is sunny, so check the forecast and carry a waterproof.
Fill up in Atami, a short way below, which has everything you need, before you climb onto the ridge. At the lookouts and rest stops you will find vending machines, a few cafes and parking, and the views are well worth the pause. Because this is a toll road, you pay on entering or leaving, and having change or an electronic card ready makes life easier. Autumn gives the clearest air and the best colours.