The iron structure also can be seen as a reminder of a struggle by African students at Hehai to preserve some semblance of a normal life in a puritanical, closed society that treats them as the ultimate outsiders.
But after two weeks that began with racial disturbances and ended in a bitter stand-off with Chinese authorities, many of the African students now say they want to give up and go home.
This time, it seems the iron fence is up to stay. Students in Nanjing already have dubbed it "The Great Wall." As such, it is a symbol of the myriad ways in which foreigners in China, particularly Africans, are constrained from free and easy friendships with Chinese.
African students endure the restrictions imposed on other foreigners, receive the same isolating and jealousy-provoking privileges and, in addition, face widespread prejudice.
"As for racism in China, like any Communist country, they tend to hide it," charged Sam Mejene, 23, an irrigation and drainage engineering student from Cameroon now studying at Hehai.
"At first you don't feel it--not until you come to understand Chinese society," he said. "So it makes it very difficult for any tourist, or anyone who just passes through China, to understand how much racism there is. We, the African students, are the victims."
The Chinese "have an illusion that black means miserable, black means poor, black means stupid," said Dauda Diakite, 25, a computer science major from Mali studying at Nanjing University.
African students, mostly men here for five years or more, also face the task of studying technical subjects in an extremely difficult language that they begin to learn only after their arrival.
Most of the 1,500 African students in China speak either French or English with fluency and thus could learn their specialties far more easily by attending schools in Europe or the United States. For nearly all, coming to China was a second choice, but a path taken because they were offered scholarships here.
Diakite said that when he first moved to Nanjing after a year of study at the Beijing Language Institute, he still could barely read his textbooks.
"I had to check the dictionary all the time," he said. "But in the library we could get books related to our major, so it helped very much. I used to read in French and English and Chinese."
Diakite said he feels he has received a solid education in computer science--partly because, as a foreign student, he was given the special privilege of more hands-on computer time than is allotted to Chinese students.
Not all African students fare as well. Because nearly all Africans have come to master specialties--not just to learn Chinese--their time is largely wasted if they fail to surmount the language barrier.
Some students find themselves totally discouraged.
"The problem of language is so severe that our diplomas are not worth anything," said one student who speaks fluent French but has been unable to master Chinese. "We don't understand what we have been taught. If you are an architect, and you construct a building, the building may fall down."
Diakite said he believes the only hope for foreign students to learn Chinese more easily "is to make some social change so foreigners can have more contact with Chinese people."