Alsemberg is a rural town with about 5,300 inhabitants in the municipality of Beersel, in the province of Flemish Brabant, Belgium, situated south of Brussels.

The name of the town combines 'Alsem', the Artemisia plant, and 'Berg', meaning 'mountain'.

The official language is Dutch (as everywhere in Flanders). Located close to Brussels, to Wallonia and the municipality with linguistic facilities of Sint-Genesius-Rode, Alsemberg is home to a minority of French-speakers.

Interesting things to do besides bicycling and walking, are a visit to the Herisem Paper Mill, and to the Visitor centre 'De Lambiek', offering information, tasting and a store, all in honour of the traditional special Lambic beers, typical for the region.

The Herisem Paper Mill

This mill is a 19th-century industrial complex that evolved from an old paper mill established in 1536. It is a well-preserved example of the once-thriving paper and cardboard industry in the Flemish Brabant region. Today, it is a recognized protected industrial heritage site, acknowledged by the European Commission as a model project for the preservation of architectural heritage in Belgium. It includes the original paper mill, cardboard factory, associated farm (with grain mill), and a centrally located residence with a former office.

The site is situated amidst 16 hectares of meadows, fields, and woodlands in the Molenbeek valley. The Herisem Mill has received awards for its preservation efforts, including the monument conservation prize in 2000 and the Tourism Award for Heritage Tourism from the Province of Flemish Brabant in 2018. The water wheels and restored Bollinckx steam engine still drive the 19th-century machinery, offering visitors a unique glimpse into the region's industrial past.

The first Belgian Water Silo