From Xidan, you can take Metro Line 4 directly to Peking University, Yuanmingyuan and the Summer Palace (Beigongmen Station), among which Yuanmingyuan Station is near the west gate of Tsinghua and Tsinghua is very close to Peking University. It is suggested that there are two schemes for tourism order.

Option 1: Take Metro Line 4 from Xidan and go to the east gate of Peking University first. After the tour, you can leave Peking University East Gate, walk about 3 kilometers north along Zhongguancun Street or take a bus to Tsinghua University Ximen Station. After the tour in Tsinghua University, you can continue to take a bus to the Summer Palace at Tsinghua University Ximen Bus Station. Finally, take a taxi from the Summer Palace to the Bird's Nest.

Option 2: Take Metro Line 4 from Xidan to the Summer Palace (that is, Beigongmen Station), then take a bus from the Summer Palace to the West Gate of Tsinghua, and it is convenient to walk or take a bus from the South Gate or West Gate of Tsinghua to Peking University, and finally take a taxi directly from Peking University to the Bird's Nest.

Note: I finally took a taxi to the Bird's Nest because it would be very tiring to reach the last destination if these scenic spots were included in the one-day itinerary, so I would take a taxi to give myself some rest time. In addition, the night scenes of the Bird's Nest and the Water Cube (National Swimming Pool) are also very beautiful. Arriving before dark can enjoy the scenery during the day and at night.

As shown in the following figure, the position marked as 4 in the figure is Xidan, which is located on the west side of Tiananmen Square, and other positions are marked as:

1 Summer Palace, Peking University, Tsinghua, Bird's Nest (National Stadium).