GLENTILT, a glen in the extreme north of Perthshire, Scotland. Beginning at the confines of Aberdeenshire, it follows a north-westerly direction excepting for the last 4 m., when it runs due S. to Blair Atholl. It is watered throughout by the Tilt, which enters the Garry after a course of 14 m., and receives on its right the Tarff, which forms some beautiful falls just above the confluence, and on the left the Fender, which has some fine falls also. The attempt of the 6th duke of Atholl (1814–1864) to close the glen to the public was successfully contested by the Scottish Rights of Way Society. The group of mountains—Carn nan Gabhar (3505 ft.), Ben y Gloe (3671) and Carn Liath (3193)—on its left side dominate the lower half of the glen. Marble of good quality is occasionally quarried in the glen, and the rock formation has attracted the attention of geologists from the time of James Hutton.