Groningen is a city of youth. 1 in 4 residents are students, and half the population is under 35. Groningen is the most bike-friendly city in the Netherlands and one of the top five in all of Europe. The large number of students living in Groningen also contributes to a diverse cultural scene for a city of its size.
In particular, the Grote Markt, the Vismarkt, the Poelestraat, and the Peperstraat are crowded every night of the week, and most bars do not close until 5 in the morning.
A lot of people (including myself until recently) would have trouble naming cities in the Netherlands other than Amsterdam and The Hague. Groningen is a city that is not well known outside of the Netherlands but has a tremendous amount to offer students. It is a true student town, with students making up 25% of the population.
Even outside of students, it is a young city as 50% of the population is under the age of 35. Groningen is compact and easy to navigate. The city center is about a 5-minute walk from the station and is filled with shops, cafes, and a large outdoor market where I had my first stroopwafel, which I highly recommend trying!