Hi, I think 2 days are enough to see some of the important places around
Atacama Desert. The popular excursion spots are Atacama Salt Lake and Toconao, Isluga national park Moon Valley near San Pedro de Atacama, Lauca National Park and Chungara Lake, Oasis de Pica, El Tatio Geysers and Puritama Hot Springs.
Atacama Salt Lake is over 100 kilometers long and offers you a great natural scenery, also visit the colonial town of Toconao which is constructed completely from volcanic stone. Moon Valley has huge sand dunes and spectacular shapes wherever you look. View this valley during sunset, it is wonderful. The Isluga national park is one of the popular tourist attractions and offers mountain tours, bicycle ridings and many things.
Don't miss to visit the Lauca National Park, the natural treasure of
Chile and having wonderful flora and fauna. It has the headwaters of Lauca river and several animals and plants can be seen in the park. Chungara Lake is one of the highest lakes in the world and the main attraction of Lauca national Park. It is the best spot for birwatching and photography.
The Puritama hot springs is located in the heart of the Atacama desert, an ideal place for travelers who enjoy relaxing amidst nature. The bath in this spring is recommended for the relief of rheumatic illnesses and stress. The fresh water in this spring has the temperature closes to 33°C and it's famous worldwide.
Only few of them are listed here, because you will be there for 2 days, so enjoy the places and have a nice trip at Atacama Desert!