There are six Cataract in set locations on the Gifts of the Nile map. Except for their movement penalty, Cataracts are identical to their surrounding river tiles. Though the movement modifier may occasionally play a role in slowing enemy naval units, they are more frequently a hindrance to nearby cities.
The six cataracts of the Nile river vary between shallows and rapids. Depending on the water level, it was possible to cross the cataracts by fording or by boat. Traditionally, Egypt claimed the portion of the Nile north of the First Cataract, while Nubia claimed the portion to the south.