This study investigates the relationship between the ancient settlements (in Lycia) and physical environmental parameters including topography, rock and soil types using GIS. Modern settlements are also included in the study to analyze if the response has changed to these parameters from past to the present. The databases created in the study include three topographic attributes (elevation, slope and aspect), rock type, soil type, ancient settlements and modern settlements. Analyses performed in the study involve distance and density analyses of ancient and modern settlements, morphological analysis, distribution of ancient and modern settlements within the rock and soil types, and visibility analysis of ancient settlements. Results of the analyses suggest that the ancient sites are located on the east, southeast, south facing and flat surfaces at slope values of 0 to 13 degrees within the elevation range of 0 to 1000 m. The average distance between the cities is 7 km preferably located over alluvium or limestone rock types with the soil types having thickness more than 20 cm. A set of decision rules are derived from the ancient settlements using above mentioned data layers to predict location of unknown settlements. This analysis indicated a few locations along the Mediterranean coast.