A novel panorama megasize environmental radon monitor (MS-ERM) is introduced using megasize polycarbonate track detector (PCTD) having some activated carbon fabric (ACF) layers on some locations. The MS-ERM is processed by panorama single-cell megasize electrochemical etching image processing system. The MS-ERM is 75 × 35 cm2 large (~1000 μm thick) which can monitor and map large environmental areas. Circular ACF layers placed on the MS-ERM can adsorb radon on its carbon active sites and enhance PCTD response by an amplification factor of ~1.5 times. The panorama MS-ERM is position sensitive resembling infinite number of single detectors assembled for providing data matrix of radon concentrations of large environmental area. A specially-designed radon chamber was constructed with 226Ra containing soil at its base for exposing MS-ERMs. Radon concentration is maximum over the radon source and decreases to a constant 222Rn concentration from few centimeters over the source up to top of the radon chamber.