The Oldest University in the Netherlands Is in Leiden (1575)
Leiden University was founded in 1575 by William of Orange, and it is the oldest surviving university in the Netherlands. The reward story is the one everybody tells. Treat it as legend with a good supporting cast. The university itself is real, and most of it is in the streets, where you can walk past it for free.
The record
William, Prince of Orange, founded the university on 8 February 1575 as a Protestant institution. The northern Netherlands needed educated men for the church and for government, and the Habsburg south had Leuven and Douai. Philip II, the king William was fighting, was still the nominal count of Holland, and his name is on the foundation certificate. He forbade his subjects to study in Leiden. Not a comfortable document to frame.
The reward story
The story goes that Leiden was given its university as a reward for holding out against the Spanish siege of 1574. Wikipedia's own wording is "it is said", and that is the right amount of confidence. Legend? Partly. The siege was real and so was the hunger. The cause-and-effect is the part that got polished. The guide to 3 October covers the siege itself.
Four centuries, one city
The first home was a convent, the Convent of Saint Barbara. In 1577 the university moved into a former beguine church, and in 1581 into a former convent of Cistercian nuns, which it still occupies. The original building on that site burned in 1616. Because it has never had a central campus, the university's history is written in the streets: some buildings are very old, others are much newer, and most are a short walk from the next one.
The people
Within fifty years of the founding, the faculty included Justus Lipsius, Joseph Scaliger, Hugo Grotius and Jacobus Arminius. By the 1640s over five hundred students from across Europe were enrolled, which made Leiden the largest Protestant university of its day. Sixteen Nobel laureates are on its record. One of them is Heike Kamerlingh Onnes, who liquefied helium here in 1908. Another is Johannes Diderik van der Waals, a different man with a different story. Keep the two straight, because the university does not always make it easy.
Where to look
The Academy Building has a room called the Zweetkamertje, the Sweat Room. Doctoral candidates waited there for their results, and the name says why. Graduates sign the walls as a rite of passage, and the room now carries thousands of signatures. It is a working building, so check the university's own pages before you go and do not expect a guided tour of the walls.
A short walk from the Academy Building is the Hortus Botanicus, the oldest botanical garden in the Netherlands and one of the oldest in the world. It is where the Dutch tulip story starts, and the tulip garden post tells that part, with the record and the legend kept apart.
Honest limits
A university town has students in it, which is the point and also the noise. Academic life runs on its own calendar, so the buildings are busiest in term time. Entry to the Hortus is charged; the streets between the buildings are free at any daylight hour. Its motto is "Bastion of Freedom", which is a large claim for a place that started with a siege reward. Judge it on the streets.