Hunter gatherers set up camps in the Amersfoort region in the Mesolithic period. Archaeologists have found traces of these camps, such as the remains of hearths, and sometimes microlithic flint objects, to the north of the city.
Remains of settlements in the Amersfoort area from around 1000 BC have been found, but the name Amersfoort, after a ford in the Amer River, today called the Eem, did not appear until the 11th century. The city grew around what is now known as the central square, theHof, where the Bishops of Utrecht established a court in order to control the "Gelderse Vallei (nl)" area. It was granted city rights in 1259 by the bishop of Utrecht, Henry I van Vianden. A first defensive wall, made out of brick, was finished around 1300. Soon after, the need for enlargement of the city became apparent and around 1380 the construction of a new wall was begun and completed around 1450. The famous Koppelpoort, a combined land and water gate, is part of this second wall. The first wall was demolished and houses were built in its place. Today's Muurhuizen (wallhouses) Street is at the exact location of the first wall; the fronts of the houses are built on top of the first city wall's foundations.
The Onze-Lieve-Vrouwentoren tower (The Tower of Our Lady) is one of the tallest medieval church towers in the Netherlands at 98 meters (322 ft). The construction of the tower and the church was started in 1444. The church was destroyed by an explosion in 1787, but the tower survived, and the layout of the church still can be discerned today through the use of different types of stone in the pavement of the open space that was created. It is now the reference point of the RD coordinate system, the coordinate grid used by the Dutch topographical service: the RD coordinates are (155.000, 463.000).
The inner city of Amersfoort has been preserved well since the Middle Ages. Apart from the Onze-Lieve-Vrouwetoren, the Koppelpoort, and the Muurhuizen
