The granite tors of Dartmoor are characterized by using the regional spatial patterns of 21 geomorphic, petrographic, and structural variables. The data were derived from topographic maps, field measurement, and laboratory analysis of rock samples collected in the field. Identification of spatial patterns and comparison of patterns between variables were made on contour maps generated from the data using ARC/INFO. Three tor types-summit tors, valleyside tors, and spur tors-are semiquantitatively characterized using these data and procedures.The three types of tors are distinguished with respect to variations in relative relief, joint spacing and joint type, rock texture, grain size, and composition. Summit tors have the highest relative relief (mean: 125.7 m), contain the most potassium feldspar (> 30 per cent), and have the most widely-spaced primary vertical (> 300 cm) and secondary horizontal joints (> 10 cm). The rocks are the most megacrystic