San Jose and Okayama became sister cities in 1957, and the friendship garden was the relationship's most visible expression. Dedicated in October 1965, the six-acre walled enclosure within Kelley Park was modeled after Okayama's Korakuen Garden, one of Japan's three great landscape gardens. The designers arranged three ponds at different elevations and connected them with flowing streams, so water moves through the garden the way it moves through Korakuen itself -- downhill, gathering presence. A year after the dedication, Okayama sent koi to stock the ponds, an act of generosity that turned a designed landscape into something breathing and alive. Pagodas, cherry trees, and stone lanterns completed the scene, but the koi became the garden's signature: bright flashes of orange and white drifting beneath footbridges.

In 2009, a cyprinid herpesvirus swept through the ponds and killed roughly ninety percent of the koi. The virus, known as KHV, is devastating to carp and has no cure once it takes hold. For a garden defined by its fish, the loss was existential. The Mercury News reported 235 koi perished. Restocking took time and care; the ponds had to be treated before new fish could safely be introduced. The garden endured, quieter than before, its waters less populated but still flowing between the three pools that give the landscape its structure. Visitors who had come to watch the koi feed found themselves noticing the garden's other qualities instead -- the way light filters through the cherry blossoms, the sound of water dropping between elevations, the surprising stillness behind the garden's walls despite the surrounding city.

The koi had barely recovered when a greater disaster arrived. In February 2017, Coyote Creek flooded catastrophically, sending water surging through low-lying parts of San Jose. The Friendship Garden, nestled in Kelley Park along the creek's path, took a direct hit. Floodwaters submerged the lower pond and most of the tea house. The main pumps that circulated water through all three ponds were destroyed. The tea house and restrooms closed to the public. Recovery was slow and underfunded. By 2022, the tea house had been repaired, but other damage lingered -- a reminder that the garden sits in a floodplain and that the same water that gives it life can also take it away. The San Jose Parks Foundation launched a dedicated fund for ongoing restoration, and the community responded, but a garden this intricate takes years to heal.

What makes this garden unusual is its hydrology. The three main ponds sit at different elevations, connected by streams that carry water from the highest pool to the lowest. This terraced design mirrors Korakuen's approach to landscape as narrative: you are meant to walk downhill with the water, encountering new views as you descend. The upper pond is the quietest, partially shaded and surrounded by mature plantings. The middle pond catches sunlight. The lower pond, the largest and most public, was where floodwaters pooled in 2017. A waterfall links two of the levels, its sound a constant backdrop. The garden is free to enter -- the city charges only for parking at Kelley Park -- and it is open daily, a pocket of designed calm in the middle of Silicon Valley's most populous city.