Gamma-ray bursts (GRBs) are the most violent explosions in the universe, seen primarily as bright, short flashes of gamma-rays. Long GRBs are most likely associated with the violent death
of a very massive star. They are thus believed to originate within regions of recent or ongoing star formation with various bright, young stars, for instance O/B associations. GRBs have been detected in gamma-rays by satellite-borne gamma-ray telescopes at MeV – GeV energies, but could potentially
also emit gamma-rays at even higher energies (Very-High-Energy [VHE] gamma-rays: E > 100 GeV), as observed by ground-based Cherenkov Telescope facilities, such as the High Energy Stereoscopic System (H.E.S.S) in Namibia. VHE gamma-rays can be absorbed by low energy photons by pair production, and the stars in the vicinity of a GRB provide a dense radiation environment,
which could lead to such absorption. We have investigated representative GRB environments and provide an estimate of the opacity to gg absorption for VHE g-rays from GRBs. We find that for the likely properties of OB associations around GRB progenitors, gamma-gamma absorption is expected to be
negligible.