Two narratives are converging: Silicon Valley’s rush to add gigawatts of AI capacity and a quiet revival of bunkers, mines, and mountains as ultra-resilient data hubs. Recent headlines point to unprecedented AI infrastructure spending tied to OpenAI. The draw is physical security, thermal stability, data sovereignty, and a narrative of longevity in an era where outages and cyber‑physical risks are rising. Geopolitics, regulation, and escalating outage impact are reshaping site selection and architectural choices. The AI build‑out collides with grid interconnection queues, water scarcity, and rising scrutiny of carbon and noise. Set hard thresholds on PUE and WUE; require real‑time telemetry and third‑party assurance.