Holop: The Echo Hall’s relic is a low‑mass resonator that taps the canyon’s natural acoustic nodes, turning sound waves into micro‑ripples in spacetime. Think of it like a crystal that, when struck, whispers back with a delayed echo that’s actually a tiny, localized warp. It’s not a device you can buy off the shelf, but if you set up a simple speaker‑driven frequency sweep and watch the echo’s phase shift, you’ll see the space‑time distortion pop up. Just don’t forget to isolate the vibration, or the whole thing turns into background noise.