Amersfoort means the ford on the Amer, the old name of the Eem river. The first written mention dates to 1028. The settlement grew at the point where the easiest route from western Holland to northern Germany crossed a marshy lowland between two ridges, the Utrecht and the Veluwe, and that geographic accident decided everything that followed. The Bishopric of Utrecht fortified the place in the twelfth century and granted it city rights in 1259. A stone wall went up in the late thirteenth century, then a second, larger wall around 1380; both still leave traces, and several of the medieval city gates remain, including the Koppelpoort, a water gate spanning the Eem that combines the functions of a bridge, a portcullis, and a fortress. The medieval city was small, dense, walled, and prosperous on cloth, beer, and pilgrim traffic. The same trade route that built the town would later carry the Amsterdam-Berlin railway through it.

On 7 March 1872, in a house at Kortegracht 11, Pieter Cornelis Mondriaan was born. The boy who would later, in Paris, drop the second 'a' from his surname and become Piet Mondrian, founder of De Stijl, painter of the red-blue-yellow grids that would shape modern design, spent his first years in this medieval Dutch town of wandering canals and crooked brick streets. The house is now the Mondriaanhuis museum, and the path between the orthogonal grid of his later paintings and the medieval irregularity of his birthplace is the shortest possible distance between two ideas of order. Amersfoort produced him; Amersfoort kept the room he was born in; and the rectangles he would eventually paint look nothing like the streets that raised him, which may be why he painted them the way he did.

The medieval industries were cloth and beer; the oldest bar in town, In Den Grooten Slock, still serves on a street where men have been drinking for six centuries. In the eighteenth century the city prospered on tobacco, grown in the local sandy soil. In the late nineteenth, the railway turned Amersfoort into a major junction, with lines branching east to Apeldoorn and Enschede, north to Zwolle and Groningen, and back west to Amsterdam and Utrecht. With railway came strategic importance: until 1980, Amersfoort was one of the biggest garrison towns in the country, and the Bernhardkazerne is still active, still housing the Cavalry Museum. The brewery De Drie Ringen, in a building older than the United States, brews beers open to the public on weekend afternoons. The city has somehow remained both a working town and a museum of itself.

The historic center is roughly circular, ringed by the old defensive moats, with the Eem river running diagonally through it from the Monnickendam in the southeast to the Koppelpoort in the northwest. The Langestraat, the main street, is the old highway from Utrecht to Zwolle and still carries the heaviest foot traffic. The Hof, the central square, hosts a Saturday market all day and a flower market every Friday at the Lieve Vrouwekerkhof. The Museum Flehite holds the Mathias Withoos panoramic painting of seventeenth-century Amersfoort, a city portrait detailed enough that scholars still use it to date individual buildings. In 2007 an international jury named Amersfoort one of the greenest cities in Europe; the historic park surrounding the urban center, and estates like Landgoed Schothorst with its English landscape gardens, are the reason.

The Onze Lieve Vrouwentoren still rises 98 meters above the rooftops, the third highest church tower in the Netherlands and one of the most recognizable medieval spires in the country. From its top, on a clear day, the geometry of the surrounding region is laid out as the surveyors of two centuries ago saw it: the Veluwe ridge to the east, the Utrecht ridge to the west, the flat marshy Valley of Gelderland between them, the Eem river curling north toward what was once a coastline. Amsterdam is 50 kilometers west, Utrecht 25 kilometers southwest, and Berlin is 600 kilometers in the direction the railway points. A tower that lost its cathedral in an explosion became the fixed point against which the rest of the country measures itself. The city around it grew to 148,000 people, with an urban region of 285,000, and is still small enough to cross on foot in twenty minutes.