Does the Keiyo Line run on reclaimed land? Old photographs from Shinkiba to Chiba Minato

Published: October 16, 2026 / About 13 min read

Were the Keiyo Line stations once sea?

The aerial photographs answer directly the question of whether the land along the Keiyo Line lies on reclaimed land. If you switch the area around the four stations of Yumenoshima / Shinkiba, Maihama, Kaihimmakuhari, and Chiba Minato to the oldest era you can choose, every station position falls on the water or in a tidal flat. Land appears only at the edges of the frame, and there the old fishing towns and the rows of houses along the highway line up in bands.

To put the answer in a word, at least for these four stations, the Keiyo Line runs over places that used to be sea. However, the four stations did not become land at the same time. Shinkiba, where the shape of an island floats up in the photograph from right after the war; Maihama, where only enclosures had been placed on the sea in the 1960s photograph; Kaihimmakuhari, where bare ground finally spreads in the 1970s photograph; and Chiba Minato, where white graded land already shines in the 1960s photograph: the way the land appears differs from station to station. The order in which the land formed and the order in which the tracks arrived do not match.

The eras when the four stations changed from water to land

The number of photographs that remain differs from location to location. At Shinkiba and Maihama you can choose seven eras, from around 1936-42 to 1987-90, while Kaihimmakuhari and Chiba Minato have five, starting from 1945-50, and they have no 1984-86 photograph either. The two stations on the side closer to Tokyo have more old photographs.

If you pick out the era in which the shape of land first appears around each station and set it beside the year the Keiyo Line station opened, the result is as follows.

At Shinkiba and Kaihimmakuhari, the order in which they became land and the order in which the tracks arrived are reversed. Shinkiba, where the shape of land appeared earliest, did not get a station until 1988, while Kaihimmakuhari, where graded land finally comes into view in the 1970s photographs, had its station open two years earlier, in 1986. The tracks did not extend in the order in which the land was made; they opened first from the Chiba side.

Shinkiba: land that floated up 40 years before the tracks

At Yumenoshima / Shinkiba, in the photograph from around 1936-42 the position where the elevated Keiyo Line tracks pass is still on the surface of the sea, and the shape of land first appears around the station in 1945-50. With the provisional opening in 1988, Shinkiba became a Keiyo Line station about 40 years after the land first appeared in the photographs. You can check how the shape of the island changed in between by stepping through the eras on the location page.

Maihama: a polygon placed on the tidal flats of a river mouth

The photographs of Maihama show even how the seashore was used before the land was born. In the photograph from around 1936-42, a branch of the lower Edo River meanders down through the middle of the frame, enclosing sandbars and patches of marsh. Land lies only along the upper edge of the frame, where strip-shaped fields and dense lots of houses line up. The station site is in the shallow sea that spreads out below, washed out white in the photograph.

In the 1945-50 photograph, groups of thin lines, like spread-out bamboo blinds, line up regularly on the water. These are rows for growing nori seaweed. The shallow sea formed by the sand and soil the river carried was divided into lots by human hands before it became land, and it was used to every corner as a place of livelihood. If you take the view that the sea also had land divisions, you can see that the straight lines of the later reclamation were not drawn on a completely blank sheet.

In Urayasu, part of the fishing rights was relinquished in 1962, and the project to reclaim the sea began in 1964. In the lower right of the 1961-69 photograph, two lots enclosed squarely by straight embankments sit diagonally side by side, and they can be read as the first move of this project. In 1974-78, a polygon edged by straight seawalls occupies most of the frame, and its inside is a patchwork of green grass and bare ground. The town name Maihama was created in November 1975, so the land born from reclamation was given a name only after its shape was complete.

If you look for the station position in the photographs, it falls on the northern edge of the polygon. In the 1974-78 photograph, a thin straight channel runs along its north side, and the old town continues beyond the channel. The Keiyo Line opened within the City of Urayasu in December 1988. Maihama Station can be called a station placed on the seam between the old shore of the river mouth and the new reclaimed land.

Kaihimmakuhari: from a sea lined with stakes to a grid of streets

In the 1945-50 photograph, the oldest you can choose at Kaihimmakuhari, land is only in the upper right corner. The coastline crosses diagonally, rows of houses are packed inside it as fine grains, and on the sea side many layers of stripes remain where the tide swept the sand. The water was so shallow that the relief of the seabed shows up as an image as it is. The station position lies offshore of these stripes.

The 1961-69 photograph records in detail how the sea was used. Small white dots are scattered across the whole water surface, drawing several diagonal bands from northwest to southeast. They line up at equal intervals because they are rows of stakes that people set up in the sea. As with the nori rows seen at Maihama, here too the shallow sea was a workplace divided into lots before it became land. Southwest of the town in the upper right, a single lot of bright land with edges cut in straight lines juts out.

The City of Chiba's chronology of Makuhari New City gives 1973 for the start of reclamation in the Makuhari district and 1980 for the completion of the grading work. The area around the station first becomes bare ground in the 1974-78 photograph and changes to a grid of streets and vacant lots in 1979-83. You can follow how the grading advanced by stepping through the eras on the location page.

The opening in 1986 came six years after the grading was completed. In the 1987-90 photograph, a long, thin structure is visible partway along the diagonally running tracks, and the blocks on its southwest side are finally beginning to fill with buildings. Brown vacant land still remains widely across the left half of the frame.

Chiba Minato: white graded land and the old shoreline

In the 1945-50 photograph of Chiba Minato, a thin, bright band of sand runs diagonally from near the upper left of the frame to the lower right corner. This is the coastline before reclamation. On the upper right side of the band, small houses are packed without gaps along the sandy beach, with rectangular fields lined up behind them. The lower left side is water all over, with fine ripples spreading, and no structures appear. The station would be built on this water side.

In the next era, 1961-69, the scene changes completely. Outside the old shoreline, flat land so white it hurts the eyes spreads out, cut into large rectangles, and there are still almost no buildings. Of the three stations in Chiba Prefecture, this is the only one where the area around the station has already become land in the 1960s photograph. Within the City of Chiba, reclamation began in Kawasaki-cho in 1940, on the Inage coast in 1961, and on the Kemigawa coast in 1967, and along the Chiba seashore the shore has been pushed out to sea step by step since before the war. The boundary between the white flat land and the old town lined with roofs traces the trail of the sand band just as it was.

In 1974-78, long buildings and round storage tanks line the graded land, and quays are attached to the water of a dug-in basin for ships. This is the land as it began to be used for handling cargo. In 1979-83, the bare ground is almost entirely filled with roofs. In the 1987-90 photograph, the graded land along the bottom edge changes into a park with curving paths and an artificial beach, and land for people is added to the land for cargo.

From a freight plan to a passenger line

Part of the reason why the order of becoming land and the order of station openings differ lies in the origins of the line. The official page of the City of Urayasu explains that the Keiyo Line was originally planned as a freight-only line for the Keiyo Industrial Region and became a passenger line at the request of the municipalities along it. Tracks that were supposed to connect the seashore lined with factories turned into transport for the residential and business areas born on the reclaimed land. The openings began from the Chiba side, and Tokyo Station was reached last.

If you lay the chronology over the eras of the photographs, the two eras 1974-78 and 1979-83 fall in the middle of the grading at Kaihimmakuhari and Maihama. The 1979-83 photograph of Kaihimmakuhari already shows a long, thin site where many tracks are bundled together, showing that the land for the tracks was laid out together with the streets before the station opened. At Maihama, in the same era an elevated road crosses the northern edge, and the straight structure running alongside that road is added from the 1987-90 photograph on. Stations differed in whether the tracks or the road took their place first on the graded land.

The four stations side by side in the same era

If you fix one era and compare the four stations side by side, you can see that the reclamation of the bay shore was not a single simultaneous construction project. A short summary of what appears around each station in the photograph of each era is as follows.

If you compare the four stations at 1945-50, only Shinkiba has the shape of land, and the remaining three stations are all shallow sea. In 1961-69, however, Chiba Minato, with its white graded land, moves a step ahead, while Maihama and Kaihimmakuhari still show how the sea was used. All four stations finally have the shape of land in 1974-78, and in 1987-90 buildings or transport structures are added at all four. The time from the land being complete to the tracks running along the whole line was only three eras of photographs.

Official land price records near the stations

Within the range available as of October 2026 (up to the 2026 publication of the official land prices (Chika Koji)), the residential areas near the four locations differ in the year their records begin. Maihama 3-chome, about 580 m from the location, started at 512,000 yen per square meter in 1993, fell to 305,000 yen in both 2013 and 2014, and was 467,000 yen in 2026. Tatsumi 1-chome, Koto Ward, about 1.9 km from Shinkiba, moved from 354,000 yen in 2013 to 694,000 yen in 2026, and Nobuto 1-chome, about 660 m from Chiba Minato, moved from 200,000 yen in 2013 to 360,000 yen in 2026.

The record for Kaihimmakuhari is for Makuhari-cho 1-chome, about 1.2 km inland; it fell from 166,000 yen in 2009 to 147,000 yen in 2013 and was 190,000 yen in 2026. This record and the Nobuto record for Chiba Minato are not values for the graded land around the stations itself.

Step forward from one era for each station

To tell whether the land along the Keiyo Line is reclaimed land, one starting era per station is enough. Open c. 1936-42 for Shinkiba, 1961-69 for Maihama, 1961-69 for Kaihimmakuhari, and 1945-50 for Chiba Minato, and from there step forward one era at a time. The moment the station position moves from water to land comes in a different era for each. The elevations at the centers of the four locations fall within the range from 2.6 m to 5.2 m, and for the expected depth of flooding on low land, each municipality's published materials are gathered on the Hazard Map Portal Site of the Ministry of Land, Infrastructure, Transport and Tourism.

The article tracing places that used to be sea with aerial photographs and maps covers, across locations, where the soil that made the land of the four stations was carried from and what you see when the reclaimed land of each area is grouped by region. The article on 60 years of the Tokyo Bay shore covers in detail how the purpose of reclamation shifted along the bay shore on the Tokyo side, and as an example of applying the reading of photographs from the same era at the stations of one line to inland hills, there is Old photographs of four stations on the Den-en-toshi Line.

The prices in this article are actual examples at each point in time and do not reflect market prices after the article was written.