National Radio Quiet Zone
A non-territorial region of the United States (in Virginia and West Virginia).
The National Radio Quiet Zone (NRQZ) was established by the Federal Communications Commission (FCC) in Docket No. 11745 (November 19, 1958) and by the Interdepartment Radio Advisory Committee (IRAC) in Document 3867/2 (March 26, 1958) to minimize possible harmful interference to the National Radio Astronomy Observatory (NRAO) in Green Bank, WV and the radio receiving facilities for the United States Navy in Sugar Grove, WV. The NRQZ is bounded by NAD-83 meridians of longitude at 78d 29m 59.0s W and 80d 29m 59.2s W and latitudes of 37d 30m 0.4s N and 39d 15m 0.4s N, and encloses a land area of approximately 13,000 square miles near the state border between Virginia and West Virginia.
-- https://science.nrao.edu/facilities/gbt/interference-protection/nrqz/nrqz#description
So basically it's all of 38,-79 in the middle, plus the eastern half of 38,-80, plus the western half of 38,-78, plus the northern half of 37,-79, plus the southern quarter of 39,-79, and corners (quarters or eighths) of 39,-78, 37,-78, 39,-80, and 37,-80. That totals about 3.5 graticules worth of angular area, which when translated into real area depends on the range of latitudes. Also, it's a mountainous region.
As the name suggests, don't be radio-noisy here (good opportunity for No Batteries Geohashes with film proof).
(map table tbd)