The Chilean Central Valley extends from the border with Peru[A] to Puerto Montt in southern Chile, with a notable interruption at Norte Chico (27°20'–33°00' S).
South of Puerto Montt the valley has a continuation as a series of marine basins up to the isthmus of Ofqui.
Some of Chile's most populous cities lie within the valley including Santiago, Temuco, Rancagua, Talca and Chillán.
[5] South of Loa River the valley continues, flanked by Cordillera Domeyko to east, until it is ends at the latitude of Taltal (25°17' S).
[11][12] The Coast Range and the Andes almost merge in two locations: one between Santiago and Rancagua and another between San Fernando and Rengo.
[14] Conglomerate of Andean provenance cover large swathes of the Central Valley being less common to the west near the Coast Range.
[11] At the latitudes of Temuco the Coast Range is subdued to such degree the Central Valley coalesces with the coastal plains.