In Mexico City, some of the main sites to see are:
The National Archiological Museum--among the best in the world
Chapultepec Castle and Park--did you know that Mexico was ruled by a French king whose palace was here?
Xochimilco--have a meal on a floating raft/boat through these gardens
Teotihuacan--very impressive pyramids about 30 miles from town that are not as large as the ones in Egypt, but are even more dramatically "decorated"
Guadalupe Shrine--where Mary (Jesus' mother) appeared to a local farmer
Zona Rosa--nightlife area near downtown
Zocalo--large central square surrounded by the government capital building and other large structures--and which is directly over another pyramid
National College--with very impressive murals on many of the buildings; and
Azteca Stadium--the main soccer (football) stadium where Mexico's national team plays all its home games.
Also, just a short ways away is the beautiful town of Cuernavaca--and a ways farther on--but still possible to visit if you don't mind a longer drive--is the silver mining town of Taxco (de Alarcon).
On the west coast are the tourist resorts of Puerto Vallarta, Acapulco, Ixtapa, Manzanillo, Puerto Escondido, and Mazatlan. Across on the Baja peninsula are the tourist resorts of Cabo San Lucas, Los Cabos, and La Paz.
I have listed these in the order of their popularity--(although Cabo San Lucas would go between Acapulco and Ixtapa on this list). My favorite Mexican resort is Cancun--but you asked for the ones on the west coast--and Puerto Vallarta is probably the best overall of these.
Enjoy
P.S. I can't comment on Puerto Escondido--as I have never been there. I have been to Cancun, Mexico City, Puerto Vallarta, Acapulco, and La Paz, however. (Cancun 2 times, Mexico City 2 times, Puerto Vallarta 3 times, Acapulco 2 times, and La Paz 1 time).
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