The Justus-Liebig-Universität Gießen, founded in 1607 as the Ludoviciana, is one of the oldest universities in Germany and the second oldest in Hesse after Marburg. It was established by Landgrave Ludwig V to compete with Marburg's Protestant university, and has produced a disproportionate share of notable scientists over the centuries — Liebig and Röntgen among them.
Today the university has around 28,000 students, making Giessen one of the most student-dense cities in Germany relative to its total population. The main campus spreads across the western side of the city centre, and its cafeterias, student bars, and bookshops give the city much of its character. The university is not a visitor destination in the conventional sense, but wandering the campus gives a good sense of why Giessen feels the way it does — young, relatively cheap, and intellectually serious in a way that doesn't announce itself.