Summer Palace (颐和园)
The Summer Palace is said to be the best preserved imperial garden in the world, and the largest of its kind still in existence in China. There was a pretend shopping district where the Qianlong Emperor could fulfill his normal life fantasies, and a huge artificial lake and mountain, all constructed for the empress dowager Cixin's 60th birthday. The lake was man made and the dug up dirt was piled up as a mountain. There was also a boat made of marble which symbolized a never failing Qing dynasty.
The Summer Palace is a good place for kids to explore. It is not as crowded as the Palace Museum and they can enjoy the different aspects it has to offer, like shopping, boat riding, and hiking.
Old Summer Palace (圆明园)
You may have heard people talk about the Old Summer Palace. In fact, the Old Summer Palace was the primary residence of Qianlong Emperor and contained extensive collection of art and historical treasures. Unfortunately, this Old Summer Palace was burned to ground in 1860. Nowadays, you can only see the remaining ruins. To learn more about its history, you can go to this Wikipedia article.
Palace of shame
The Summer Palace and the Old Summer Palace has a long history of being looted and burned by foreigners, especially during the Second Opium War and the Eight-Nation Alliance. When the subject is brought up, it still evokes strong emotion among some Chinese. Interestingly, one of the prominent figures during that time, Lord Elgin, was once the Governor General in Canada. Many places in Canada, especially in Ontario, were named after him.
Beijing Olympic Park
After the Beijing Olympic in 2008, the government turned the site into a park. In this expansive area, you can get up close to the two most impressive architectures, the Bird Nest (Beijing National Stadium), and the Water Cube (Beijing National Aquatics Center). The Bird Nest is open to public for a small entrance fee of CNY 50 and will host the opening and closing ceremonies of 2022 Winter Olympics and 2022 Winter Paralympics. It will be the only stadium to host both the Summer and Winter Olympics and Paralympics opening ceremonies. The Water Cube is now home to the Asia's largest water park that is open to public for entertainment.