Visit the city center. Get on a bus and travel to the coast vina del mar for a day. use the metro it is fast and easy transport

It all depends on the time of year. Air quality in the winter can be bad so avoid July and August if you can. best time are from November to May. for souvenirs go to bella vista area, there are lots of shops selling Lapiz lazuli mounted in silver jewellery. sit and have a coffee in Plaza de armas and browse the artists selling their paintings and have dinner in Patio bella vista. If you're a wine lover then you have to do a winery tour. there are lots around and prices can vary.

Take the Red tour. It is a free walking tour through the mais spots of the city. It leaves from Plaza de Armas.

Go to Providencia. You can take the bus from the airport to the underground-Pajaritos station! It's very cheap! In Pajaritos you buy the "metro"ticket. From Pajaritos, you have to wait until "Los Leones" station". This is the Providencia area. From here you can go shopping, eat typical food in some chilean restaurant (I recommend you "Liguria", a restaurant with typical chilean speciality). Good luck!

Be sure to go to San Cristobal and Cerro Santa Lucía. In three days you can do some cool stuff, just getting organized, despite the city being grande.O city tour bus is also worth are 2hs ride that is done for the whole city. Ahh if you want to do some shopping good go to the Mall Arauco has many shopping options

walk in the centre (la moneda, cathedral, ...), check the view from cerro santa lucia, buy some earings or musical instrument in the market under that hill, visit cerro san cristobal and eat emapanadas, drink pisco and stay at hostal sammy :) (that s pretty much what i have done and i liked it a lot)

Have a taxi tour in the city if you want to see everything. Donwtown you can check the city center. Go to Providencia area, Los Condes area. There are nice bars, restaurants, young people around. Closer to the Andes. (Eat an "hamburguesa")

ski! or eat the road side pasties