  Cosmic Ray (CR) interactions with the dense gas inside Giant Molecular Clouds
(GMCs) produce neutral pions, which in turn decay into gamma rays. Thus, the
gamma ray emission from GMCs is a direct tracer of the cosmic ray density and
the matter density inside the clouds. Detection of enhanced TeV emission from
GMCs, i.e., an emission significantly larger than what is expected from the
average Galactic cosmic rays illuminating the cloud, can imply a variation in
the local cosmic ray density, due to, for example, the presence of a recent
accelerator in proximity to the cloud. Such gamma-ray observations can be
crucial in probing the cosmic ray distribution across our Galaxy, but are
complicated to perform with present generation Imaging Atmospheric Cherenkov
Telescopes (IACTs). These studies require differentiating between the strong
cosmic-ray induced background, the large scale diffuse emission, and the
emission from the clouds, which is difficult to the small field of view of
present generation IACTs. In this contribution, we use H.E.S.S. data collected
over 16 years to search for TeV emission from GMCs in the inner molecular
galacto-centric ring of our Galaxy. We implement a 3D FoV likelihood technique,
and simultaneously model the hadronic background, the galactic diffuse emission
and the emission expected from known VHE sources to probe for excess TeV gamma
ray emission from GMCs.
