Former sites of regional expositions. Portopia, the Yokohama Exposition, and Yokatopia as they once were

Published: October 15, 2026 / About 13 min read

Exposition sites did not go back to vacant land

If you trace six venues of regional expositions held, or planned to be held, in various parts of the country from the 1960s to the 1990s, such as Portopia, the Yokohama Exposition, and Yokatopia, most of the venues were land whose reclamation had only just been finished. At the five that were held, there is no place where the whole venue went back to vacant land after the closing; parts of the pavilions, the division of the venue into lots, and the terrain of a hill were carried over to the former sites. The giant Ferris wheel in Yokohama moved to another place and kept running, and in Fukuoka the building of the theme pavilion became the city's museum. When you look for a former site, the shortest route is to go back and forth between the aerial photograph closest to the time of the venue and the photograph as of 2026.

Six former venues are taken up here. They are Portopia '81 at Port Island, the Yokohama Exposition at Minato Mirai, Yokatopia at Momochihama, the Himeji Grand Exposition on Mount Tegara, which enters the frame of Himeji Station North Casty 21, the World Resort Expo at Wakayama Marina City, and the World City Expo at Daiba, which ended without being held. There are locations where the time of the venue overlaps an era of the photographs and locations where only the appearance from before the exposition period remains, and that difference divides the ways of reading the former sites.

The six venues and the photograph eras closest to their exposition periods

For each venue, the year it was held and the era of the photograph closest to the exposition period are lined up.

If you read the table down the columns, the four places where the exposition period itself falls within an era of the photographs are Port Island, Minato Mirai, Momochihama, and Mount Tegara. At Wakayama Marina City the eras of the photographs stop at 1984-86, and the appearance of the exposition venue is not yet shown. At Daiba the 1987-90 photograph only conveys the appearance of grading from before the planned exposition period, and the day it was used as an exposition venue never came.

In the elevation column, the five on reclaimed land fall between 1.9 and 5.8 m at the center, and only Himeji Station North is 10.8 m. The value for Himeji Station North was measured on the north side of the station and is not the height of Mount Tegara.

The former Portopia site: Port Island in 1979-83

According to the chronology of the port of the City of Kobe, Portopia '81 was an exposition held in 1981 to commemorate the completion of the island. The 1979-83 photograph of Port Island brackets that year, and in the open land enclosed by lines in the center of the island, buildings with colored roofs are gathered in a small group. It is less a finished town than an appearance in which only the lots of the venue were prepared first, and if you step to 1984-86, tall buildings line up on the same lots. The grading of the island and its spread offshore are covered in the article tracing the reclaimed land of Osaka Bay.

The former Yokohama Exposition site: the graded land and the Ferris wheel of Minato Mirai

According to a brief chronology of the City of Yokohama, work on the Minato Mirai 21 project began in 1983, the Yokohama Exposition ran from March 25 to October 1, 1989, and the venue was the Minato Mirai 21 district. Six years after work began, at a time when most of the blocks still had no buildings, the graded land itself was used as the venue.

The photographs of Minato Mirai go from 1974-78 straight to 1987-90. If you step across the gap of more than ten years between them, the central area once occupied by a shipyard and freight tracks has changed into flat, sand-colored graded land. Even though the lines of the roads dividing the lots have been drawn, only round outlines and buildings scattered here and there sit on them, and you can read that the shape of the roads was decided ahead of the shape of the town. Another thing to see in the photograph of this era is that the bundle of tracks toward the top of the frame has thinned.

The leading example of what remained after the closing is the giant Ferris wheel. According to Yokohama Cosmo World, Cosmo Clock 21 was born as a pavilion of the Yokohama Exposition, and it was decided to keep it after the exposition ended. Later, in step with the development of the district, it was moved in March 1999, and it keeps running, having changed place along with the amusement park. It is an example of equipment made for the venue that became a landmark of the town while being moved in step with the development of the former site.

Only two places, here and Momochihama, have the year of the exposition period and the era of the photographs both at 1987-90. The 1987-90 photograph preserves the ground just after it was prepared as the venue, as it was before high-rise buildings stood in rows. If you switch from there to the photograph as of 2026, most of the empty lots have been filled with buildings, and the share of built-up area within a 500 m radius has also grown from 10% in 1976 to 81% in 2021. If you want to read from the era of the shipyard docks and the freight yard, the article tracing reclaimed land is the way in.

The former Yokatopia site: the theme pavilion that remained at Momochihama

According to the materials of the Fukuoka City Museum, the Asian-Pacific Exposition, known affectionately by the name Yokatopia, was an exposition held in 1989 in the Seaside Momochi district to commemorate the 100th anniversary of the city's municipal status. On the reclaimed land of the Seaside Momochi district that became the venue too, the completion of the land and the holding of the exposition overlapped at almost the same time.

The 1987-90 photograph of Momochihama shows the ground at the time when wide lots with few buildings were being used as the venue. If you switch to the photograph as of 2026, Fukuoka Tower, the museum, and high-rise apartment buildings have entered the same lots, and the surfaces that were empty are almost filled.

One of the buildings that decided the use of the former site is the museum. The Fukuoka City Museum opened in October 1990, and ahead of its opening it was used as the theme pavilion at the 1989 exposition. A building used at the exposition opened its doors as the city's museum in the year after the closing. Whereas the Ferris wheel in Yokohama remained by moving to another place, in Fukuoka the building remained in the same place, and that is the difference.

After the closing, the lots of the venue divided into a cultural and business area with the museum and the tower, and blocks of housing toward the south. The share of built-up area within a 500 m radius of Momochihama grew from 0% in 1976 to 31% in 2021. The appearance of the beach before reclamation is not covered in this article and is left to the photographs of the old eras on the location page of Momochihama.

The former Himeji Grand Exposition site: Mount Tegara enters the lower left of the frame

Of the six, Himeji is the only one whose venue is not on reclaimed land. According to the City of Himeji, the venue of the Himeji Grand Exposition, held in 1966, was Mount Tegara, and a monorail opened on a section of about 1.8 km linking the venue and Himeji Station. Because of sluggish use, the monorail was suspended in 1974 and abolished in 1979.

Himeji Station North Casty 21 is a location centered on the former freight yard on the north side of the station, but the hill of Mount Tegara reaches into the lower left of the frame. In the 1961-69 photograph, south beyond the station, where paddies and fields spread, you can see that ponds and gardens have been made on the hill. This photograph is from an era that includes the year the exposition was held, so it captures the outline of the hill prepared as the venue.

If you step to 1974-78, the oval of an athletics stadium stands out white within the green of the hill. This photograph is from about ten years after the closing, and the hill of the venue has taken on the appearance of a park holding sports facilities. The green of the hill and the outlines of the ponds remain in the photograph as of 2026 as well, and in contrast to the former venues on reclaimed land, which were filled with buildings within a few years, the terrain of the venue itself has remained for more than half a century.

Traces of the monorail were also carried on as a facility. According to the City of Himeji, the building used as Tegarayama Station while the monorail was running opened on April 29, 2011 as Tegarayama Koryu Station, and its second floor is a monorail exhibition room. The span of time in which the transport built for the exposition was suspended after eight years and the station building turned into a place for exhibits 45 years after its opening is a point of interest that the former venues on reclaimed land do not have.

The former World Resort Expo site: Wakayama Marina City was born after the photographs

In the chronology of the public relations magazine of Wakayama Prefecture, Wakayama Marina City was completed in 1994, and the World Resort Expo was held for a period of 72 days. Here too the completion of the land and the exposition overlap in the same year, but this place differs from the other venues in that no photograph from an era close to the exposition period is at hand.

The past photographs you can switch to at Wakayama Marina City go only up to 1984-86, and no era shows the appearance of the venue. If you jump to the photograph as of 2026, rows of boats lined up at the landing piers and wide paving in the southern half appear. The land prepared as the venue was carried on after the closing as a place for leisure and for keeping boats, and the name of the marina remained.

The World City Expo that was never held, and Daiba in 1987-90

In a discussion of looking for former exposition venues, Daiba is the only place where the term former site does not apply. According to the chronology of Tokyo, the World City Expo, which was planned to be held in the Waterfront Subcenter, was canceled by a decision in May 1995, and in November of the same year the Yurikamome Line opened. The new transit line that was to carry people to the venue began running with no exposition.

The photographs of Daiba cover seven eras from around 1936-42 to 1987-90, but in none of the eras can any movement of lots that looks like an exposition venue be found. The changes from the bare ground of Reclaimed Land No. 13 to the construction of the bridge can be followed by stepping through the eras on the location page.

At Port Island, the lots prepared for the venue became the framework of the town after the closing. At Daiba, that procedure stopped partway, and the prepared grounds came to wait for another use without passing through an exposition. If you switch from 1987-90 to the photograph as of 2026, buildings and roads sit on the surfaces that were bare ground. Lining up these six places is interesting because you can compare in photographs both venues that were held and a venue that was not, while they share the same starting point of an exposition.

The things left at the former venues fall into three types

If you rearrange the six places by what remained after the closing, the ways the former sites were carried on fall roughly into three types.

The first is the type in which the land and the lots prepared as the venue are carried over to the town as they are, and Port Island and Wakayama Marina City fall into it. At Port Island, the lines that enclosed the blocks in the photograph from around the year of the exposition have become the outlines of blocks lined with buildings in the photograph a few years later. The second is the type in which a building of the venue gains another role in the same place. The theme pavilion in Fukuoka became a museum, and the station building in Himeji became a facility holding a monorail exhibition room. The third is the type in which equipment survives by moving to another place, and the giant Ferris wheel in Yokohama is the example.

Depending on which of the three types a place falls into, the things you should look for in the photographs also change. For the type in which lots remain, you need to compare the lines of the roads; for the type in which buildings remain, the positions of buildings in the photograph from the same era as the exposition period; and for the type that moved, both the time of the venue and the photograph as of 2026. Daiba is an example outside these types, where the grounds of the venue became a town without passing through an exposition.

Step through the photograph eras to check the former venues

For every former venue, the starting point is the photograph from the era closest to the exposition period, and from there you step one at a time forward and back. For Port Island the starting point is 1979-83, for Minato Mirai and Momochihama it is 1987-90, and for Himeji Station North Casty 21 it is 1961-69. For Wakayama Marina City, which has no photograph from the time of the venue, go back and forth between the two photographs from 1984-86 and as of 2026, and for Daiba, follow in order from the bare ground of 1974-78 to the construction of 1987-90.

The appearance from the eras when these places were sea or port grounds before the expositions is covered in detail in the article tracing reclaimed land and the article on the reclaimed land of Osaka Bay.