Pyu Ivvi's Zubat Cove is an inset into the cliffs just beyond the town's small harbour.
Descriptions from Sessions
Collected from Arsaga:
And as they reach the port, passing past the crassly vertical - if not very high - cliff face and onto the wooden structures built across the waves, they can see the gym, though it takes the craning of their heads to do so. It's set into a cavern elevated above the waves, off to their collective right when coming down that path. Or, well, it seems to be - the only real indicator are heavy rope bridges ranking up towards it, and the flag that's being held out of the cavern by a long pole vanishing into its depths, rippling in the wind, depicting a purely mythical dragon, with a stylised pokéball above and below it, the blotches of red making the purpose obvious. The wind whips at the flag, creasing its folds, causing its silken surface to appear almost iridescent, or like water itself, mercilessly at whim of the elements, its bottom end fringed from all the beatings given to it by the gusts.
As they cross the last half of the way across the bridges, the inside of the cavern becomes visible. It's not lit by anything but daylight, and the shadows cast by the cliff itself make it hard to discern much inside it, but there's a small platform of stone immediately by the bridge, though the rest of the cavern seems entirely ragged in its entire depth… which, all things considered, isn't much. One could probably climb down the platform and cross over to where a dome-like, ivory-coloured building sits nestled, but not only does that seem tedious, but potentially dangerous. The cavern is alive with the sounds of Zubat - clung to the shadowed part of the cavern walls, fluttering to and fro, and generally seeming to have claimed the cavern for themselves. Despite this, calmly, a Spearow is perched on a pole set into a manmade hole on the smooth surface of the stone platform, peering at Marcus, head tilted curiously. One of its talons is locked around a short scroll of sorts.
The Spearow tilts its head the other way as Marcus begins his question, before cawing almost aggressively, its feathers spiking outward, and spreading its wings what at first appears to be threateningly. Then it visible inhales, before pushing itself away from the post - leaving the scroll to roll about on the top of it ever so slightly - and veers around, flapping its small wings and carrying its light body across the cavern in direction of the ivory building. Time to read the scroll, then?
On the scroll, a beautifully elaborate handwriting greets them. “Welcome, travellers, to the Pyu Ivvi pokémon gym. While you're reading this, Hayato is notifying me of your arrival. I ask that you please be patient for the while.” Oh, how curious, so that's what the Spearow was doing? “If you have come to battle, gym rules are two on two with no swap-outs allowed. Loss by K.O., death, or the touch of a Zubat, which you have no doubt noticed inhabit this cavern to hundreds.”
A new paragraph. “When Hayato returns, whatever your concerns, please write them onto the back of this note and give it to him. If you wish a dialogue, I will send a pokémon to FLY you across to my domain. For all other concerns, I recommend staying at the platform.” The signature takes up generous amounts of space. 'Tove Zipporah'.
It seems like a small miracle that the swarm did not take off entirely and rained past the visitors and out into broad daylight, but the inward thanks goes unstated. Why Tove chose to live there, subjecting the badgequesters to the torment of many wings, is hard to say. Perhaps that was its purpose - torment. Either way, the group's hurried down from the cavern and across the bridge, then back to the solid ground of the port and cobblestone path back up to the meadows.
If Nikki were to move into the building [Tove lived in, set into the back of the pokégym's arena], she'd notice it was indeed quite small, and, in fact, consisted only of a single room, however spaceous, with only the bathroom encapsulated in a compartment off to the right, breaking the spherical nature of the inside with that straight wall.