City of Tournai

The location of Tournai, as is often the case with cities, is not accidental but linked to a geomorphological context.

The historic location of Tournai is closely tied to a ford across the Scheldt, precisely where a geological limestone threshold affected the river, creating an ideal crossing point for people and animals.

Small boats could sail as far as the threshold; beyond the shallow stretch, transport by ship was limited or impossible.

Tournai therefore served as a transshipment point (“transshipment point”) where goods were transferred between different modes of transport because of this natural barrier.

This made it an ideal location for an early trading settlement.

A similar geological setting can also be found in Halle, albeit on the Zenne and with a threshold caused by the rock of the Brabant Massif.

Tournai is therefore one of Belgium’s oldest cities, founded at a strategic crossroads along the Scheldt. The presence of a ford was essential for travel and trade, both in prehistoric times and during the Roman and medieval periods.

Beneath Tournai and the surrounding area lies a limestone formation, also known as “Tournai limestone,” more than 100 metres thick in places. This rock is hard, strongly dolomitised, often rich in flint, and extremely resistant to wear. Where this limestone reached the riverbed of the Scheldt, it (still) limits the rate of erosion, creating a threshold and a bend in the riverbed.

Thanks to this geological threshold, Tournai was exceptionally well suited for settlement and trade: people could safely cross the river on foot or by wagon, which was important when bridges were lacking in early history. This explains why a city arose here in particular, and why this location has been of economic, strategic, and military importance since Roman times.

Pascal Brackman