Passing from the coast to the tableland, a distinct climatic region is entered.
The basin is comparatively narrow, and the Tagus, like the other rivers of the Iberian tableland, generally flows in a rather confined valley, often at the bottom of a rocky gorge below the general level of the adjacent country.
The edges of the protaxis are in general its highest parts, and the rivers flowing outwards often have a descent of several hundred feet in a few miles towards the Great Lakes, the St Lawrence or the Atlantic, and in some cases they have cut back deep gorges or canyons into the tableland.
It is situated on a high tableland.
Horizontally stratified tableland.
