Sulzer-Areal, Industrial heritage site in Winterthur, Switzerland.

The Sulzer-Areal is a former industrial site of roughly 20 hectares southwest of Winterthur's main station, between Zürcherstrasse and the railway tracks. It is divided into sub-areas such as Halle 87, Halle 710, the Katharina-Sulzer-Platz, the Kesselhaus and the Lokstadt, where old factory halls stand next to new housing and offices.

The Sulzer brothers founded their first bronze foundry here in 1834, outside Winterthur's old town on the road to Zurich, and built the associated residential and office building the same year. The works expanded between the Zurichstrasse and the new railway line, and by the second half of the 19th century the firm employed over 33,000 people worldwide, occupying a site comparable in size to the old town. Heavy industry moved out at the end of the 1980s, making the 150,000 m² area one of Switzerland's first industrial brownfields; the 1989 "Winti Nova" demolition plan met fierce opposition, and the 1992 international competition was won by Jean Nouvel and Emanuel Cattani's "Megalou" project, abandoned in summer 2001.

Halle 87, the former City Halle, hosted musicals by composer Harry Schärer for 13 years, including Space Dream from 2001 to 2011; since 2015 it has housed the ZHAW main library. Halle 710, opened in 2012, holds a regular weekly market with local products. The Kesselhaus now contains a multiplex cinema and shops.

The area lies southwest of Winterthur main station, between Zürcherstrasse and the railway tracks, and covers about 20 hectares. Halle 710 hosts a weekly market with local products; the Kesselhaus holds a cinema and shops. Parts are still used industrially, so some zones are fenced off.

The Lokstadt section of the former Sulzer works is planned as a mixed quarter with up to 6,500 workplaces and housing for 1,500 residents, of which 30% of the residential floor area is reserved for affordable housing. The site also holds one of Switzerland's earliest industrial brownfields, vacated when heavy industry moved out at the end of the 1980s.