The River Tilt follows a geological fault through the hills for much of its length through Glen Tilt, entering the River Garry after a course of 14 miles, then receiving the River Tarf on the right, which forms some beautiful falls just above the confluence, and on the left the Fender, which has some fine falls also. The massive mountain of Beinn a' Ghlò and its three Munros Càrn nan Gabhar (1129 m), Bràigh Coire Chruinn-bhalgain (1070 m) and Càrn Liath (975) dominate the glen's eastern lower half. Why not take the Glen Tilt Trail, suitable for walking and cycling.

Marble of good quality was occasionally quarried in Glen Tilt, and the rock formation has long attracted the attention of geologists. One of the earliest was James Hutton who visited the glen in 1785 in search of boulders with granite penetrating metamorphic schists in a way which indicated that the granite had been molten at the time. This showed to him that granite formed from cooling of molten rock, contradicting the ideas of Neptunism of that time that theorised that rocks were formed by precipitation out of water. Hutton concluded that the granite must be younger than the schists. This was one of the findings that led him to develop his theory of Plutonism and the concept of an immensely long geologic time scale with "no vestige of a beginning, no prospect of an end".