Speaking half-apologetically, the estate agent mentioned that the house was beside an ankyo. Hideo Takayama and his fiancée were inspecting what might become their future home in Ikenoue, Setagaya-ku, and it was the first time they had encountered the term. 渠 (an) denotes a ditch or canal, while 暗 (kyo) signifies darkness or disappearance. Combined, they form ankyo (暗渠), which translates directly to dark canal. This somewhat eerie word refers to a waterway that has been covered and built over—a concealed stream or river. Depending on one's perspective, a local ankyo is not always viewed as an attractive property feature.

Several years passed before Takayama's marriage ended. He vacated his ankyo home and settled into a modest apartment alone. Nowadays, he is interviewed across various media with some regularity, and each time, he reflects on his origin story, including the transitional period following his divorce. It was a time of emotional lightness and freedom from his previous life. Yet, it was equally defined by a search for direction, spending his days ambling through the city on a well-worn bicycle.

From his new neighbourhood, a web of narrow paths connected areas such as Sakura-Shinmachi, Toritsu-Daigaku, and Sangenjaya—a collection of refined locales served by the south-westerly Den-en-toshi and Tōyoko train lines. Drawn to these backstreets, Takayama researched their origins and discovered that they had been constructed over old riverbeds, marking his second encounter with ankyo. He found that the paths mirrored the meandering courses of their original waterways, naturally threading through valleys and avoiding steep inclines. Quiet, convenient and free of cars, these discreet shortcuts between destinations were perfect for casual cycling. 

Rivers and canals were essential to daily life during the Edo period (1603–1868), forming a historic waterway network often compared to Venice's. These waterways supported commerce, culture, transportation, and agriculture. The existence of ankyo can be traced to their conversion into underground drainage systems, a process driven by successive waves of urban reconstruction after the Great Kanto Earthquake in 1923 and the aftermath of World War II, and subsequently, the rapid urbanisation of the 1960s.

With Tokyo's expansion, its previously vital aquatic networks were increasingly seen as hindrances to modern infrastructure. With industrialisation and a rising population, they became sources of pollution. Rivers and canals were now challenges to overcome, especially in the drive to sanitise the city for global presentation ahead of the 1964 Tokyo Olympics. As a result, many were buried, giving rise to ankyo. Urban features such as roads and housing were subsequently constructed atop these concealed channels.

Takayama recounts walking along ankyo paths, unable to escape a sense of loneliness and exclusion. The ankyo, forgotten and stripped of their identity as rivers, had been relegated to obscurity. Along many ankyo, accumulated debris and refuse form miniature ruins. Weeds grow high and moss blankets surfaces. Takayama came to see himself in the ankyo—during his marriage, he had felt estranged and unappreciated, reduced to a shadow of himself. Whether by his actions or the influence of others, he had been sealed off from the world. His heart, as he saw it, was an ankyo; his inner river buried beneath the surface. 

However, even the most neglected ankyo still carry faint traces of their past for those who look closely. Should you come across a stretch of paving flanked by crumbling balustrades that feels like a bridge but somehow is not, the answer to the riddle is that you are likely standing atop an ankyo. Their legacy persists in place names, such as those ending in ~kawa-dōri (川緑道), meaning "river street," or ~bashi kōsaten (橋交差点), meaning "bridge intersection." Subtle shifts in elevation and the ebb and flow of winding paths further hint at hidden rivers. 

Takayama began to see these features as more than traces of the rivers' past—they were expressions of resilience and dignity, preserved against the odds. He recalls this moment as a turning point when he resolved to rediscover the "self" buried during his marriage. This realisation ignited his fascination with ankyo, leading to authoring books and producing television programmes on the topic. Alongside Nama Yoshimura, he co-founded Ankyo Maniacs, a group devoted to giving lectures, organising exhibitions, and leading ankyo tours. 

I've encountered few urban researchers who draw such a direct connection between their fascination with the city and matters of the heart as Hideo Takayama does. A seemingly obscure feature of urban topography serves as a lens through which he can understand his emotional world. A year ago, when I hesitantly sent out the first edition of Tokyothèque¹ to its initial ten readers, I posed a similar question rooted in psychogeography: how does urban sprawl bring peace to my heart? I have yet to fully uncover my core wound, as Takayama did in his beloved ankyo streets, but his conceptual metaphor brings me a step closer to understanding it.

Regular readers may remember that I once lived in Ikenoue, not so far from Takayama's old home, near a covered tributary of the Kitazawa River. At the time, without realising their significance, I wandered many ankyo streets, often using them as spaces for reflection. Practically speaking, these streets also offer a compelling framework for urban exploration. While Tokyo's exact number of ankyo remains undocumented, it likely surpasses 100. I've included a selection of my recent ankyo walks for your reference.

Momozono River Greenway

The Momozono River Greenway is a 2.3-kilometre walking trail built on the former Momozono River. It was converted into an ankyo relatively recently, between 1985 and 1994. I chose to walk this route at night; though daytime might seem the natural choice, the path was well-lit and peaceful after dark. Occasionally, a jogger passed by, underscoring the safety of such secluded streets even late at night. The greenway meanders eastward from the Chūō-Sobu Line tracks near Asagaya Station in Suginami-ku, eventually joining the Kanda River, which flows northward, marking the border between Nakano-ku and Shinjuku-ku. The path has a community arts feel, with approximately 90 plant species, sculptures, mural walls, and graphic tiles depicting plant and animal themes.

Kuhonbutsu River Greenway

The Kuhonbutsu River Greenway was established in 1974 after the Kuhonbutsu River was transformed into an ankyo. The walkway has Somei Yoshino cherry trees, Satsuki azaleas, and Kinmokusei fragrant olives. On a warm autumn afternoon, I followed the greenway from Jiyugaoka Station, where boutiques and cafés spill onto the path, to the residential tranquillity of Midorigaoka Station. In the 1990s, benches were introduced to curb illegal bicycle parking. Today, they shape the promenade's character at the Jiyugoaka end, creating a relaxed space where people can spend leisurely afternoons reading or hanging out with friends. 

Shibuya River Street

The Momozonogawa and Kuhonbutsugawa greenways illustrate two distinct possibilities for ankyo: serene sources of urban greenery and lively centres of activity. Each appeals to city dwellers beyond the niche of urban explorers. Shibuya River Street, however, might represent the ultimate redemption of an ankyo street. Opened in 2018, it saw the Shibuya River uncovered, shedding its status as an ankyo. The river was revitalised as a clean waterway—a complex project requiring coordination and long-term planning involving contributions from urban designers, municipal staff, and private developers. Its 600-metre greenway, where walkway and river run side by side, connects Daikanyama to Shibuya, culminating at Shibuya Stream, the city’s most en vogue multi-functional complex.

Perhaps each of us carries our own ankyo—a concealed part of ourselves, borne heavily through life. To push Hideo Takayama's extended metaphor further: if ankyo represent facets of oneself buried by years of struggle, and their former names and features can evoke a memory of our past vitality, then the transformations seen in these three examples serve as proof that re-emergence and renewal are always possible. No matter how deeply the essence of oneself is buried, it can flow again, surging forth in a renewed current of life. 

Until we meet on a dark canal,

AJ

Pins and More

This week's ankyo street walks have been added to the Tokyothēque Master Map, and the Ankyo Maniacs book details are listed in our ever-expanding bibliography. If you'd like access to these resources and wish to support the public-facing, freely available work that is Tokyothèque, you can become a supporting member here.

Footnotes

Tokyothèque #1: Tokyo Arrivals