Next time you grab a tub of icecream from your freezer, spare a thought for Carlo Gatti, the Swiss entrepreneur who popularised the treat in this country. Domestic refrigerators being thin on the ground in the 1860s, Gatti had to ship natural ice from Norway - a practice referred to as The Death Trade by the unfortunate sailors who had to man the often less than seaworthy vessels - and then transport it through London's waterways to his ice warehouse on the Nash-designed Regent's Canal.

Tucked away in a quiet street behind King's Cross station, that warehouse is now the London Canal Museum, a quiet repository of information about a colourful strand of our capital's history. Mindful of its genesis, the museum is excavating one of the two vast ice wells beneath the building. It was here that Gatti stored his hard-won product before selling it on to caterers, butchers and the public. As you peer down into this vertiginous pit, the clammy atmosphere rises to meet your skin, prompting visions of the hand-chafing labour that once took place in its belly.

The museum's artefacts and visual displays tell the story of London's canals, from their origins as trade routes through to their current use as supporters of various leisure pursuits, but it is the integration of the building itself into that history which fascinates. Authentic areas have been renovated, missing parts recreated and the whole sprinkled with ephemera such as ice-cream ads and moulds, and primary-coloured pottery. Downstairs, a full-size narrow boat in the middle of the room has been cut in half to expose its traditional interior, while the hand-pulled ice-cream delivery carts used by Gatti's employees line the walls. The space upstairs was once a stable for the horses who pulled both the narrowboats along the towpaths and the larger ice-delivery carts; apparently a goat had the job of keeping the equine contingent calm, though we are not told whether he achieved this through strength of personality or strategic use of horn.

Perched on the side of Battlebridge Basin, the museum overlooks a tranquil mooring for the narrowboats now used as homes or as tourist "gondolas" and this location can be glimpsed in one of the entertaining films available at the museum's video point. Resembling a recruitment ad for the industry, Barging Through London, 1924 follows a coal-laden boat on its journey from Limehouse Docks into the city's interior, via bucolic scenes of jolly citizens waving from the garden gates of their water-edge properties, the boat's calm progress contrasted with the hustle and bustle of the streets lining the way. Watching the horses amble along the towpaths, it's difficult to believe that the ropes harnessing them to the boats could have engendered sufficient friction to create the beautiful curlicues still visible on the iron poles which protect the corners of stone bridges.

Gatti's of London was dissolved in 1983, but Carlo's descendants must experience a frisson of pleasure when they learn how their Swiss-Italian forebear's story is being told in this calm corner of London - and how tightly that story is woven into the city's own history.

London Canal Museum, 12-13 New Wharf Road, King's Cross, N1 (0171-713 0836) 10am-4.30pm Tues to Sun, Adult pounds 2.50, concs/child pounds 1.25