In the past, towns and water went together. The terrible state of most roads meant it was easier to transport goods by sea or river than by land. In the 18th century, the arrival of the canals stimulated trade, in the 19th, the docks brought prosperity to many Victorian cities.

After the Second World War, the impact of the lorry, the aeroplane and new forms of shipping goods ensured that swathes of Britain's old Docklands became redundant. Liverpool, Hull and Gloucester in particular have risen to the challenge of finding imaginative new uses for old places. But the most amazing transformation of them all is, of course, the Canary Wharf project, London's own "Manhattan on the River Thames".

There is no need to go through the familiar teething problems: the lack of the tube link, the recession, the uneasy relationship with local residents. What remains invigorating is the contrast between old and new.

Walk away from the tower, flanked by its attendant offices of glass, steel and marble towards the old entrance of West India Dock, opened in 1802. Suddenly, a grouping of elegant and inevitably much smaller buildings grab the eye.

There is the guard house of 1803, built as a lock-up and armoury. Nearby are the sugar warehouses, with spiked window glazing to stop theft, and also the Cannon Workshops, originally used for storage. A stone's throw away is the Dockmaster's House of 1807, one of the finest of all industrial buildings, which later became the Jamaica Tavern.

Stretches of imposing wall emphasise that the West India Dock was built in order to prevent pilfering. Originally, ships had discharged their goods in the middle of the Thames, producing a "thieves' paradise". Of the workforce of some 37,000 employed on or about the Thames at the end of the 18th century, one third were thought to be professional criminals. Not surprisingly, the architect who built this enclosed dock, a Mr DA Alexander, had also been responsible for Dartmoor Prison.

But there has been loss, too. Walk up West India Dock Road towards the Docklands Light Railway. The extension of Westferry station brought oblivion for one of the East End's renowned pubs, Charlie Brown's, named after the famous local figure and former sailor who turned his watering-hole into an informal museum. When he died in 1932, huge crowds followed the funeral to Tower Hamlets Cemetery.

Best of all is Garford Street on the left, with its collection of small but perfectly formed cottages. Once the homes of the dock police, naturally the sergeant occupied the largest dwelling in the middle. The four constables had to make do with those on either side. Somehow the cottages take us back to a time when police work was more gentle and less aggressive.

The former dock police cottages are in Garford St, London E14