Yes,you can. These two sites are near each other.

Thanks Isabella. After visiting these 2 summer palaces. Will I have time to visit the Bird Nest (Olympic stadium)? Thanks again!

A thorough visit of the Summer Palace and the Old Summer Palace need almost a complete day. Bird Nest is beautiful at night than in the broad day. So you can have spend most of the day visiting those two sites and spend late afternoon and evening visiting the Bird Nest.

Thanks Isabella. What are the opening hrs. of the Bird Nest?