The 'Tombolo' name comes from the Italian term for a sandbar connecting an island to the mainland.
The path consists of four distinct rocky islands, locally referred to as Sanshiro-jima.
The width of the exposed path changes based on the tidal range, which is influenced by the lunar cycle.
The area is part of the Izu Peninsula Geopark, recognized for its complex volcanic history.
Local folklore suggests the name Sanshiro comes from a historical legend involving a man of the same name, though geological evidence remains the site's primary draw.
The Tombolo Land Bridge in Nishina, Nishiizu, is a rare geological phenomenon where a gravel path emerges from the sea at low tide to connect the mainland to Sanshiro Island. This natural causeway is formed by the accumulation of sediment transported by waves and tides between the coast and the offshore rocks. The bridge is composed of three small islands, known as Sanshiro-jima, which are revealed sequentially as water levels drop. Visitors can walk across the rocky path to explore the tide pools and shoreline of the island when the tide is sufficiently low. The formation is a designated natural monument of Nishiizu Town due to its unique sedimentary structure. The path typically disappears completely during high tide, making the island accessible only during specific windows throughout the day.
From the elevated observation point on the mainland shore looking down at the path as it emerges.
Check the official Nishiizu town website for the daily tide forecast before departing, as access is entirely dependent on water levels.
Wear sturdy, water-resistant footwear with good grip to navigate the uneven, slippery, and sharp gravel path safely.
Bring a change of socks or quick-drying footwear, as the path is often submerged in shallow, cold seawater.
Attempting to cross when the tide is already rising, as the water can return quickly and cut off the path to the mainland.
The path is entirely dependent on tidal cycles; there are no fixed opening hours and access is restricted daily by high tide.
Avoid removing rocks or shells from the tide pools to maintain the local ecosystem; stay aware of the rising tide to avoid being stranded.
