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Sensing the Aquarium vol.1｜
Aquariums Come Alive at Night

A New Way to Experience Aquariums After Dark

There is a quality to aquariums at night that daytime simply cannot offer.
The special lights playing across the tanks. A beer in hand as you watch the fish drift by. Music rising up through the floor beneath your feet.
Urban aquariums like Sumida Aquarium in Tokyo — with its "Night Aquarium" programme — and AOAO SAPPORO — with its "AOAO NIGHT" — are capitalising on their city-centre locations to meet the growing appetite for an evening out after work. In recent years, the sweltering heat of summer has also played a role: more and more visitors are choosing to come at night to escape the midday sun.
Meanwhile, suburban aquariums have begun hosting special night-time events of their own. Facilities that ordinarily close in the early evening open their doors during summer holidays and selected periods, offering programmes built around creatures that can only be observed once darkness falls.
The chance to witness the lively movements of nocturnal fish, or a pair of penguins standing asleep — real, unscripted behaviour that the night alone makes visible — has become one of the defining formats of aquarium events today.

The Real Reason Behind Night-Mode Lighting

Night-mode lighting is a hallmark of the nocturnal aquarium experience — but the dimly atmospheric effect has less to do with setting a romantic mood for couples, and more to do with the wellbeing of the animals themselves.
At AOAO SAPPORO, for instance, the team does not simply lower the lights at night; they also adjust the duration of "daylight" across the four seasons. Even in a fully indoor environment, many facilities report that their animals read seasonal cues and display breeding behaviours at the expected times each year.
Behind the careful crafting of this nocturnal environment lies a deep curatorial wisdom — one that honours the natural rhythms of living creatures.

Does Darkness Sharpen Your Senses?

For those of us who live in cities, true darkness is a rare thing. That is precisely what makes the "night aquarium" — an experience akin to walking through a forest after midnight — something genuinely apart from the everyday.
In the dark, less information reaches us through our eyes, and senses we rarely use in ordinary life begin to stir. Things we overlooked in broad daylight can suddenly become apparent.
Darkness also softens the hard edges of a building — its walls and corners fade — and the sense of artificiality recedes. Perhaps for the city-dweller, simply being immersed in darkness is enough to reawaken a feeling of nature that daily life has quietly buried.

Remove the Corners and the World Changes

I believe that the disappearance of a building's sharp corners has a particularly powerful effect in exhibition spaces.
Consider the Taito City Asakura Choso Museum, a five-minute walk from Nippori Station in Tokyo. The sculptor Fumio Asakura designed his own atelier here, and throughout the space he used aru-kabe — curved, rounded walls with no sharp angles. The intention was to prevent unwanted vertical lines from appearing in the background when viewing sculpture. In practice, the result is a space filled with soft light in which the works are beautifully set off, and in which one feels remarkably at ease.
Photography is not permitted in that building, so let me offer another example: the galleries of Yokosuka Museum of Art in Kanagawa Prefecture also feature curved aru-kabe walls. Here, the eye travels through the exhibition without ever being interrupted by a corner. The circular windows cut to admit natural light are quietly beautiful as well.

Aquariums, too, sometimes feature dome-shaped rooms or spaces with rounded corners — an approach that strips away extraneous lines and information, directing the visitor's gaze entirely towards the living world inside the tank.

▼In Closing

For me, the particular magic of the night aquarium can be traced to two things above all:

　① The chance to encounter the nocturnal life of animals
　② The way darkness sharpens the visitor's senses

A night aquarium is a different world from the one you visit in daylight. If you have never experienced it, I encourage you to go — just once.
A strange and quietly transformative hour may be waiting for you there.

Ayako Horikawa

Founder, DESIGN STUDIO KAISUI
An experience designer specializing in aquariums, working across exhibition design, spatial design, and program development.
After gaining experience in operations and exhibition design at Sumida Aquarium and spatial design at UDS Ltd., she established her own studio. She has been involved in exhibition direction and program development for the urban aquarium AOAO SAPPORO.
Her work focuses on designing environments that cultivate observation, curiosity, and wonder.
She holds a Master’s degree from Tokyo University of the Arts.
Author of “A Day in the Life of Aquariums: Creatures and People” (Fukuinkan Shoten).
Member of the Japan Society of Exhibition Studies and JAGDA.