Santiago: the Bip card, the smog season, and the earthquake drill

Santiago's metro is excellent and requires a Bip card, bought at any station; the Transantiago buses use the same card. From May to August, winter smog settles in the valley and air quality alerts are common; the Andes disappear from view. Chile has frequent earthquakes and strict building codes; if one happens, stay where you are, away from windows, and don't run outside. Petty theft happens around Plaza de Armas and on the metro at rush hour; keep bags in front.