3. Venice
Overcrowding can dampen the magic of Italy's floating treasure, but once tourists are tucked up in bed a different atmosphere takes shape. Like a starry sky, St Mark's mosaic facade sparkles golden, and in the absence of noisy distractions it's a beauty to behold. A labyrinth of calles and empty bridges allows imaginations to run wild through Renaissance times, while a taste of late-night modern living can be found in the cicchetti bars spilling from Cannaregio.
4. Lisbon
Inside windowless salons lit only by lamps, it's easy to lose track of hours, months and years. Some institutions in the Portuguese capital have resisted change, serving drinks in art nouveau surroundings until at least 3am. Bars in Bairro Alto overflow to become a street party in the early hours.
5. Berlin
Meals, music and parties are available any hour of the day. People-watch at techno giant Berghain and canal-side chill-out Club der Visionaere; sink into a sofa in one of the squat-style bars lining Kreuzberg and Neukolln. For the best views, climb the Reichstag or Fernsehturm until midnight.
6. Singapore
This island state satisfies appetites with midnight snacks. Chomp Chomp Food Centre keep woks fired up until late; or combine dining with souvenir shopping in Bugis Street Market, open until 11pm.
7. Tromso
Sometimes there's too much going on after dark, making sleep feel like a waste of time. When night finally falls in this Norwegian city above the Arctic Circle, it creates a backdrop for one of nature's greatest displays. Drive into surrounding forests on a mission to hunt for the aurora borealis or climb along mountain ridges for even clearer views. In summer, days are endless when the sun shines for 24 hours.
8. Sydney
Whether it's the surf rolling on to Sydney's beaches or reflections of skyscrapers in the calmharbour, water takes on a different quality when the moon glows. But it's in the pre-dawn hours that this city really shines. Strap into a harness and climb the Harbour Bridge at 4.30am; or head down to Bondi Beach and watch surfers.
9. Marrakech
The Medina never sleeps. Metal and glass lanterns cascade a kaleidoscope of lights and cloaked Berbers waft like ghosts along medieval stone tunnels. In Jemaa el-Fnaa, smoke coils from grills until 1am, scenting the air with paprika and cumin as storytellers entertain crowds. Stay up until 5am, when a call to prayer echoes from minarets and trays of mint tea warm up the day.
10. Buenos Aires
With restaurant kitchens sizzling steaks until the early hours there's no rush to eat meals, and sipping malbec in queues on street corners is all part of the fun. Digest enormous dinners by flitting between speakeasy bars in Palermo and slip into an all-night milonga at Salon Canning.
The science of sleep
Some people only need five hours to feel their best the next day, while others need nearer 10. Some people are morning people or "larks" who find it easy to rise and shine, whereas others, the so-called "owls" struggle in the morning and are at their best in the evening. Essentially for a good night's sleep, you need two things: (1) to sleep in darkness during the biological night and (2) to foster a feeling of safety and security.
These two things are interlinked. Human nocturnal vision is poor, so we have to find somewhere safe to sleep. It also means we have to rely on our other senses, particularly hearing, in order to remain vigilant to threats in the environment. It is these two factors that cause our sleep to be disturbed when we travel.
This is of course most obviously seen when we experience jet lag, when we are trying to sleep counter to the timing of our circadian rhythm. But it can also be seen in what we call the "first night effect", the difficulty adjusting to the sounds associated with sleeping in a new place. The brain is forced to remain vigilant in case these new sounds represent danger.
The best way to combat jet lag is fairly simple: if it is light stay awake; if it is dark go to sleep.
● Dr Neil Stanley is the author of How to Sleep Well.
