Brauerei Feldschlösschen is Switzerland's largest brewery, located in Rheinfelden in the canton of Aargau. The brewery takes its name from the castle-like brewery building — "Feldschlösschen" translates to "little castle in the fields" — which remains an iconic landmark to this day. Founded in the nineteenth century, it has grown into the dominant brewing force in the Swiss beer market, with a history deeply intertwined with the country's brewing tradition. Feldschlösschen produces a wide range of beers, from classic Swiss lagers to alcohol-free variants, serving both the domestic market and international export channels. The brewery has been part of the Carlsberg Group, one of the world's leading brewing conglomerates, which has shaped its production scale and distribution reach across Europe and beyond. Its portfolio is anchored by accessible, well-crafted lagers that have made it a household name throughout Switzerland. The brewery site in Rheinfelden is also a visitor attraction, offering guided tours through the historic brewery building. According to visitor reviews, knowledgeable guides walk guests through both the rich history of the brewery and the beer production process. The castle-like architecture of the site makes it one of the most visually distinctive brewery experiences in Switzerland.