There were shells in the rock.
Walking along Kamogaura, I stopped at a flat slab of stone near the water’s edge. The surface was marked with unmistakable outlines — the ribbed curves of bivalve shells, pressed into the rock as if stamped there deliberately. I touched one. It didn’t budge. It wasn’t resting on the stone; it was the stone.
“These are fossils.”
I would have walked right past them if I hadn’t been watching the ground.
Noto Was Once the Seafloor
The geology of Noto Peninsula makes this make sense immediately.
Most of the rock that forms Noto was laid down during the Neogene period — roughly 23 million to 2.6 million years ago — when this region sat beneath a shallow sea. Over millions of years, sand and mud accumulated on the seafloor, layer by layer. The creatures living there — clams, scallops, and other shellfish — died and were gradually entombed in those accumulating sediments.
Then tectonic forces pushed the seabed upward. What had been the bottom of the Sea of Japan became a peninsula. Waves eroded the exposed rock and shaped the coastline we walk today.
The fossil shells at Kamogaura aren’t curiosities dropped on the surface. The rock around them is what formed on an ancient seafloor, millions of years before humans arrived.
Two Entirely Different Oceans in One Cove
Kamogaura also gave us one of the more striking physical demonstrations I’ve seen on any coast.
On the seaward side of the rocky reef, the Sea of Japan threw itself against the stone. Spray flew up. The sound was low and constant. On the landward side — just steps away — we found water so calm and clear we could see the bottom detail by detail.
Same location. Completely different sea states.
The reef itself is doing the work. The jagged rock formation juts out toward the open ocean and functions as a natural breakwater, absorbing the energy of incoming swells before they reach the sheltered inner cove. It’s a small-scale version of something that defines the whole peninsula: the outer coast (Sotouura, facing the Sea of Japan to the northwest) takes the full force of winter storms, while the inner coast (Uchinomi, facing Nanao Bay to the east) sits in perpetual calm.
Noto is both coasts at once, divided by a ridge of uplifted Neogene rock.
”You Have to Send This to Tamorisan” — Excitement at Tsukumo Bay
A short drive from Kamogaura brought us to Tsukumo Bay (九十九湾), and my travel companion became immediately absorbed in the rocks.
“This stone is incredible — Tamorisan would love this” — phone already out, crouching to get a better angle.
Tsukumo Bay is a ria coast: a drowned river valley. When the last ice age ended and sea levels rose (a transgression known in Japan as the Jōmon Transgression), seawater flooded the valleys that rivers had carved into the hills. The result is this intricate network of inlets with water so still and clear that the seafloor is visible from the elevated walkway.
Geology became a shared language for the afternoon.
Why Shiroyone Senmaida Exists Where It Does
Heading west along the outer coast, we reached Shiroyone Senmaida — the Thousand Rice Terraces, a UNESCO Globally Important Agricultural Heritage site. Steep stone-walled paddies descend from the forested hills directly to the edge of the Sea of Japan.
Terraced agriculture is a response to constraint. Where slopes are too steep and flat land too scarce to build large paddies, farmers built small ones — hundreds of them, tiered down the hillside. On Noto’s outer coast, the mountains press close to the shore with almost no flat ground between. That topography is itself a product of the same Neogene uplift that created Kamogaura’s fossils: land pushed skyward, then planed down by the sea.
We climbed the stone steps to find what is reportedly the second-smallest paddy in the field. Calves earned it.
Practical Notes
Kamogaura (鴨ヶ浦)
- Wajima City, Ishikawa Prefecture. Small parking area off National Route 249
- A walking path leads out to the tip of the rocky headland — watch footing on uneven stone
- Visit at low tide to access more of the reef surface
Tsukumo Bay (九十九湾遊歩道)
- Noto-cho, Hōsu District, Ishikawa Prefecture. Parking available nearby
- The elevated walkway runs close to the water; the bay’s clarity makes it worth taking slowly
Shiroyone Senmaida (白米千枚田)
- Shiroyone, Wajima City. Roadside station “Senmaida Pocket Park” has parking
- Wear shoes you can climb stone steps in — some sections are steep
Dinner: Wajima-mon (わじもん) We ended the day in central Wajima. Fugu karaage, Noto beef seared tableside, grilled tachiuo (beltfish) — every dish was locally sourced and none of them missed. It wasn’t showing up in Google reviews when we visited, but we’d found it through a local recommendation on social media. Worth seeking out.
Geological references: Geological Survey of Japan, AIST (Seamless Geological Map of Japan); Geospatial Information Authority of Japan topographic maps.
Statements marked “believed to” or “thought to” reflect current scientific consensus and may involve some uncertainty.