Mexico City's Metro Line 9 is the brown line. Twelve stations cut a swath across the city from east to west, and provide much-needed relief for the sometimes crowded Line 1. Both lines start at Pantitlán and reach Tacubaya. Line 1 does it with 19 stops. Line 9 does it in just 12.
It's not entirely a "locals-only" line. For international guests, the stations above, sometimes high above, Ciudad Deportiva can be inspiring. Given seasonal differences, sometimes the views can be even heart-rending.
From Tacubaya to giant, Metro Pantitlán, every trip is a voyage into a past that's never stopped breathing. Tacubaya is an ancient town where springs fed the lake from the west. Pantitlán is where some of that water, forced into a narrower culvert, splashed its way to the giant Lake Texcoco in the east.