The parks along the Costanera are nice for a bike ride or walk without turning it into a big hike, same with Cerro Santo Lucia. The big Parque Metropolitano/Cerro San Cristobal is good for an afternoon of hiking. Barrio Italia is a nice place to stroll around, and isn't very busy with people.
The subway system works well, and it's a safe way to get around the city. Worth tracking down a Tarjeta Bip.
Chile, un destino clave con productos de marcas de prestigio y tecnología a precios que representan un tercio de lo que cuestan en Argentina, además de una amplia variedad de ofertas turísticas en sus playas