Landsfort Herle was a fortification with moat. It was probably built by the counts van Ahr-Hochstaden (also referd to as Here van Are). The name Landsfort (‘fort of the land’) comes from the fact that the fortification come under the responsibility of the land. In the 13th century Heerlen, and thus also Landsfort Herle, come in to the possession of the Dukes of Brabant, the Landsfort was (re)built by the Dukes of Brabant in 1244.
The wall is believed to be one of the oldest still recognisable in the Netherlands, part is now being excavated. A marquette of the fort was constructed from a map form 1787 found while the Pancratiuskerk was heavily reconstructed in the 1960s. The fort had three gates and had two towers (the bell tower of the church and the Schelmentoren, both with 2 metre thick walls).
In the roof of the church were little rooms for the inhabitants of Heerlen to take shelter in case of hostilities, unfortunately these rooms were destroyed when a, supposedly German, bomb hit the church at New Year's Eve 1944/1945.
References:The Broch of Gurness is an Iron Age broch village. Settlement here began sometime between 500 and 200 BC. At the centre of the settlement is a stone tower or broch, which once probably reached a height of around 10 metres. Its interior is divided into sections by upright slabs. The tower features two skins of drystone walls, with stone-floored galleries in between. These are accessed by steps. Stone ledges suggest that there was once an upper storey with a timber floor. The roof would have been thatched, surrounded by a wall walk linked by stairs to the ground floor. The broch features two hearths and a subterranean stone cistern with steps leading down into it. It is thought to have some religious significance, relating to an Iron Age cult of the underground.
The remains of the central tower are up to 3.6 metres high, and the stone walls are up to 4.1 metres thick.