Fuller's Griffin Brewery on the Thames at Chiswick was the last remaining traditional brewery in London for many years, and its distinctive malt-and-hops smell has been part of the Chiswick atmosphere for centuries. The brewery offers guided tours that take visitors through the brewing process from grain to glass, including a tasting session at the end.
Tours run regularly and should be booked in advance, particularly at weekends. The adjacent Mawson Arms pub is the brewery tap, a Victorian pub where you can drink Fuller's beers at the source. Even if you skip the tour, walking past the brewery and catching the smell of brewing wafting across from the river is one of the more specifically London experiences available in this part of the city.