The road south from Erfoud is dotted with fossil workshops where the local dark limestone — rich in 400-million-year-old marine fossils — is cut, polished, and sold. Macro Fossiles Kasbah is the largest and runs short guided tours that take you through the sawing yard, the polishing floor, and the showroom. You can watch ammonites and orthoceras emerge from the rock under the saws, and buy anything from a small polished slab to a full dining table.
Prices are negotiable, particularly for smaller pieces; the larger items can be shipped. Even if you have no intention of buying, the workshops are worth a stop for a sense of one of the strangest of Saharan industries.