The Memorial Site of the 4th National Congress of the Communist Party of China in Shanghai reopened to the public on Monday following six months of upgrading.

Located in Hongkou district, the memorial site now covers 3,040 square meters, up from 1,839 sq m.

"The upgraded memorial hall will further explore, protect and publicize its abundant Party history resources, and provide vivid education materials for the history learning and education activities of the Party across the city and the country," said Guo Fang, secretary of the Hongkou district committee.

The 4th National Congress of the Communist Party of China was held from Jan 11 to 22 in 1925 in a room at what is today 254 Dongbaoxing Road.

The original site of the congress, a shikumen residential building, was destroyed during the war in 1932 and rebuilt in 2006.

Tong Ke, the curator of the memorial hall, said the upgrade allows it to reproduce the vivid scene of the 4th National Congress through interactive multimedia technology such as augmented reality, providing visitors with an immersive viewing experience.

"We restored the old Shanghai lane around the venue, such as the cobblestone pavement and grey brick wall," Tong said.

"Also, we hope to combine Red culture with the trendy culture that young people pay attention to. For example, we've prepared many surprises by using AR technology and visitors can scan the code of a cultural relic or building to find hidden exhibition content."

Newly added artworks, including oil paintings, sculptures and Chinese paintings, are other highlights of the exhibition, Tong said. Among the works is a famous painting by Zhang Peichu that shows representatives attending the 4th National Congress.

The first daily newspaper in CPC history and 14 congress documents are also on display.

The memorial hall has also dedicated space to host Shanghai's first national flag education exhibition, which displays precious historical materials such as the design manuscripts, calligraphy and paintings of Zeng Liansong, the designer of the national flag.

"The audience will also have the chance to see the national flag signed by Zeng Liansong, the national flag used in the flag-raising ceremony at Shanghai People's Square during the 50th anniversary of the founding of the People's Republic of China, and the five-star red flag sewn in the White Residence prison by revolutionaries," Tong said.