Heerlen (Dutch pronunciation: [ˈɦeːrlə(n)] ⓘ; Limburgish: Heële [ˈɦeə˦lə]) is a city and a municipality in the southeast of the Netherlands.

Heerlen forms part of the city-region of Parkstad Limburg, an agglomeration with about 250,000 inhabitants and encompassing 8 municipalities.

After its early Roman beginnings and a modest medieval period, Heerlen became a centre for the coal mining industry in the Netherlands in the late 19th century.

In the 20th century, architect Frits Peutz played a major role in shaping the city as we know it today.

They founded a military settlement, named Coriovallum on the crossroad of two main roads: Boulogne sur Mer - Cologne and Xanten - Aachen - Trier.

Farmhouses and mills are built across the valleys of Caumerbeek, Schandelerbeek and Geleenbeek and medieval Heerlen slowly takes shape.

Through these fortifications, Heerlen acquired some rights and freedoms, which gave it an elevated status over the surrounding countryside.

Voerendaal, Hoensbroek, Schaesberg en Nieuwenhagen now fell under the legislation of the so-called "Land van Herle".

During the Eighty Years' War (1568–1648), Heerlen was disputed by the kingdom of Spain and the Dutch Protestant rebels and swapped sides several times.

At the 1661 Partage Treaty, Heerlen became part of "Staat-Limburg", ruled by the States-General of the newly founded Dutch Republic.

This resulted in it bordering the territory of the Spanish Netherlands, causing it to remain quite isolated from the rest of the state until 1793, when the French conquered Heerlen.

The Dutch government tried to ease the pain by moving several governmental offices (ABP, CBS) to Heerlen but even today the city has not fully recovered from the loss of tens of thousands of jobs.

Heerlen was also the location of the now-defunct University of Theology and Pastorate (Universiteit van Theologie en Pastoraat or UTP in Dutch), which had to close down due to lack of students.

Health care in Heerlen (and the rest of the Parkstad Limburg) is provided by Stichting Gezondheidszorg Oostelijk Zuid-Limburg (G.O.Z.L.).

In 1935 Heerlen's most famous landmark building, the Glaspaleis, was built next to the medieval church in the centre of the then modest town.

It is one of the most outstanding examples of early Modernism in The Netherlands but it was only recognized as such at a fairly late stage (after it had been badly maimed).

The renovation has now been completed and it now houses several of the city's cultural institutions, including a museum of modern art.