Wolf's Hole Quarry SSSI and possible RIGS at Bridge of Allan, Stirling; feldspar-phyric basalt lava flow (Ochil Volcanic Formation)at top of quarry face rests on an undulating surface formed by the sandstones of the Scone Sandstone Formation (Lower Devonian). The sandstones were used to build Bridge of Allan Spa in the 19th century and the rock face is popular with local climbers as well as UKRIGS Conference 2003 delegates.