Compressional tectonics of the Tertiary age created large structures in the easternmost part of the Akal horst, in the Campeche Sound, offshore Campeche, Mexico (Figure 1). Prolific fields such as Cantarell, Sihil, Ku, Abakatún, Taratunich, and Bacab are on those structures. The tremendous magnitude of these structural events left very little evidence (have masked the presence) of the Mesozoic extensional system. For these reasons, much effort has been dedicated to explaining the compressional tectonic events and associated structural styles while the importance of the Mesozoic extensional system has been underestimated or minimized. Our current work suggests that some of these large structures are more closely related to the Mesozoic extensional tectonics than previously thought.