What is the main reason why Cambridge is one of the best-known towns in the world?

Cambridge must be one of the best-known towns in the world, and can be found on most tourists’ lists of places to visit. The main reason for its fame is its universities which started during the 13th century and grew steadily. Until today there are more than twenty colleges.
    The oldest college is Peterhouse, which was founded in 1284, and the most recent is Robinson College, which was opened in 1977.  The most famous is probably King’s College, because of its magnificent church.
    The university was exclusively for men until 1871 when the first women’s college was opened. Another was opened two years later and a third in 1954. In the 1960s, most colleges opened their doors to both men and women. Almost all the colleges are now mixed, but it will be many years before there are equal numbers of both sexes.