Tonopah is at the outcropping of a number of ledges which continue for several hundred feet below the surface for an unknown distance.
The creek flowed over a succession of rock ledges and formed pools at the edge where tadpoles swam.
The Aughrabies or Hundred Falls, as they are called, are divided by ledges, reefs and islets, the last named often assuming fantastic shapes.
South of Cohasset the shore is sandy, with a few isolated rocky ledges and boulders.
The surface is formed of cement moulded over metal gimmel-work, and arranged to form ledges and boulders, peaks and escarpments, and faced with coloured sand and paint.
