The HYDRA camp is Krausberg tucked between these two mountain ranges.
Hearing that a number of soldiers have gone missing at a nearby HYDRA encampment, Steve takes it on himself to rescue them.
The Caerwent Training Area, a now defunct military base, was used as the HYDRA camp exterior in Krausberg where Captain America rescues the Howling Commandos from captivity.
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(Captain America: The First Avenger, 2011)
MCU: Location Scout 