I'm quite a fan of short-haul flights, so long as they're canal locks. They offer a best-of-all-worlds cycling experience: gentle freewheel downhill; scenic waterscape; and sometimes, a lock-keeper's cottage isolated from the road system where a ruddy-faced chap in a self-knit sweater has a sideline in home-made pickles or carvings.
Britain's longest canal downhill, the 30-lock monster serpent at Tardebigge near Bromsgrove, has a towpath but it's 'not officially open for cycling', according to British Waterways. (I intend to investigate just how not officially open it is at some point soon.)
Caen Hill's famous 16-ish-lock staircase (above right) just outside Devizes is visually more impressive, being as straight as a cycle pump, and as wheezy if you try to bike up it, and welcomes cyclists too. (There's a chapter about it in my book.)
Five Rise Locks at Bingley (right) is shorter (but, being in Yorkshire, steeper and tougher) and is also a cycling frisson.
London cyclists can enjoy the gravity-assisted tour of locks on Regent's Canal and Hertford Union, but the towpaths often duck under bridges in an alarmingly narrow and twisted way, so you have to keep getting off.
So the best London lock-flypast is on the Grand Union Canal at Hanwell Locks (right), about a mile or so before Brentford, as the canal starts its final descent south to join the Thames. It's a sequence of half-a-dozen locks with a pleasantly wide, curving towpath, and connects the vivid little-India melee of Southall with the shiny little-Singapore office blocks of Brentford, and the little-England riverside village of Old Isleworth lauded two days ago.
So we recommend downhill canals. Perfect riding for a summer's evening. And from your position of freewheeling ease you can gongoozle at the narrowboaters hacking through the locks. Watching honest toilers engaged in tedious, repetitive tasks for minimal gain may enlighten you as to how your line manager feels when they see you working in the office.