One of the great joys of travelling is stumbling across unexpected places, wandering without a single destination in mind and embracing the journey. These places are perfect for just that – so abandon the map, leave the sat nav behind and let the road take you where it will.

1. The Mercato, Addis Ababa, Ethiopia

Crowded, cramped and rough around the edges, the Mercato covers several square miles of Ethiopia’s capital city. Reputedly the busiest market in Africa, it’s a fascinating place to explore, with traders peddling their wares out of corrugated-iron shacks amidst a fug of incense, coffee and cow dung. This is very much a market for locals, with sections selling grain, vegetables, tyres and used white goods, but you can still pick up an interesting piece of jewellery or other tourist trinkets if you wish.

The Mercato, Addis Ababa, Ethiopia

2. The Hermitage, St Petersburg, Russia

The Hermitage quite simply has the largest collection of paintings in the world, and is set in one of the most beautiful buildings in Russia: the Winter Palace, an opulent Baroque confection that served as the official residence of the tsars until the revolution of 1917. The museum contains more than three million treasures and works of art, from ancient Scythian gold to paintings by Picasso, only a fraction of which are on display at any one time.

The Hermitage, St Petersburg, Russia

3. Bock Casemates, Luxembourg City, Luxembourg

Part of Luxembourg City’s impressive series of fortifications, designated a UNESCO World Heritage site in 1994, the dark, dank Bock Casemates were carved out of a sandstone promontory overlooking the Alzette valley in the sixteenth and seventeenth centuries. The extraordinary complex of underground passages and galleries ran for 23km (17km still remain), and at one time housed a 1200-strong garrison, along with bakeries, kitchens, stables and the like.

Bock Casemates, Luxembourg City, Luxembourg

4. Knossos, Crete, Greece

You won’t be the first person to get lost at the Palace of Knossos. Many of the visitors that wander amongst the courtyards, storerooms and royal apartments that made up the largest Minoan palace in Crete are tempted here by the legend of its labyrinth, and of the Minotaur, the creature it was built to contain. Whilst there’s no sign of the labyrinth today, you can still peer into some of the palace’s remaining rooms, which once numbered a thousand.

Knossos, Crete, Greece

5. The Grand Bazaar, Istanbul, Turkey

The world’s largest covered market, Istanbul’s suitably named Grand Bazaar has been trading goods on the same spot in historic Sultanahmet for more than 550 years. Browsing is an endurance sport here, all the more so given the enthusiastic sales techniques on display, and with more than 4000 shops crammed under one roof, you’ll need to pick your battles – try bartering with the shoe-sellers on Kavaflar Sokak or the gold merchants on Kalpakçilar Başı, or the carpet-sellers everywhere in between.

The Grand Bazaar, Istanbul, Turkey

6. Kolmanskop, Namibia

Stand in the middle of the old town hall in Kolmanskop and you’ll find yourself knee-deep in sand. Kolmanskop sprung up when diamonds where discovered here in the early 1900s – but it faded just as quickly once the gems petered out, and it was abandoned to the mercy of the desert in the mid-1950s. Today, it’s an eerie ghost town, its once-grand buildings – including a ballroom, theatre and casino – slowly succumbing to the encroaching dunes.

Kolmanskop, Namibia

7. Old Delhi, India

Founded in 1638 as the capital of Mughal India, Shahjahanabad (or Old Delhi) is the most intense and downright chaotic area of the city. Delhi is home to nearly 17 million people, and at times it can feel like most of them are jostling along Chandi Chowk, the heaving main thoroughfare, or in the surrounding warren of streets, where rickshaws and handcarts hurry between bazaars selling everything from spices to wedding garlands to car parts.

Old Delhi, India

8. The Moscow metro, Russia

Perhaps only in Moscow can a lengthy trip on the underground become a journey of artistic beauty. The system was designed in the 1930s to showcase the glories of Mother Russia, and many of the first few lines to open employed the most renowned Soviet architects of their time. There are 195 stations to wander, neck craned, gawping at decor ranging from High Stalinist opulence (think red marble, gold-encrusted mosaics and bronze lamps) to the utilitarianism that defined 1970s USSR.

The Moscow metro, Russia

9. Shinsegae Centum City, Busan, South Korea

Shinsegae Centum City is officially the largest shopping complex in the world – they’ve even got a certificate from the Guinness Book of World Records to prove it. This is three million square feet of retail therapy, with over 425 shops filling sixteen floors. Plus there’s a food market, an art gallery, an ice rink, a three-floor spa, a multiplex cinema, a gym, a roof garden and the world’s largest indoor driving range, of course.

Shinsegae Centum City, Busan, South Korea

10. The temples of Angkor, Cambodia

The biggest archaeological site on earth, the temples of Angkor are scattered over some four hundred square kilometres of countryside in northwest Cambodia. For six hundred years from the early ninth century, successive Angkorian kings constructed their royal cities and state temples here – the magnificent Angkor Wat is just the most famous of myriad monuments, among them the ancient walled city of Angkor Thom, and Ta Prohm, its crumbling ruins engulfed in a tangle of creepers and strangler figs.

The temples of Angkor, Cambodia

11. Fez el Bali, Fez, Morocco

The extraordinary Medina of Fez el Bali is an addictive maze of blind alleys and dead-end lanes. You can follow Talâa Kebira, the main thoroughfare, down into its bowels, past goods-laden donkeys and ancient fondouks selling olive oils and a dozen types of honey. Metalworkers hammer away at immense copper cauldrons on Place Seffarine, brightly coloured yarns dry in the heat on Souk Sabbaghine, and workers toil knee-deep in the honeycomb of vats that make up the tanneries Chouwara.

Fez el Bali, Fez, Morocco

12. Kumbh Mela Festival, Allahabad, India

The largest religious gathering on earth, Kumbh Mela takes place every three years, alternating between Allahabad, Haridwar, Nasik and Ujjain. The cities are auspicious with Hindus thanks to their location at the confluence of holy rivers, and a staggering nineteen million pilgrims attended the last Maha (“Great”) Kumbh Mela in Allahabad in 2013, when the surrounding floodplains were turned into a vast tent city and legions of naked sadhus, their bodies covered in ash, plunged into the waters each morning.

Kumbh Mela Festival, Allahabad, India

13. Palace of Parliament, Bucharest, Romania

If ever a building defined its builder, then the Palace of Parliament is it. The enormous centrepiece of Bucharest’s Centru Civic was constructed in the 1980s for Nicolae Ceauşescu, Romania’s Communist dictator, and is regarded as the concrete zenith of his megalomania. Allegedly the second-largest administrative building in the world (after the Pentagon), the “Madman’s House”, as it was once popularly known, has well over a thousand rooms and took some seven hundred architects to put together.

Palace of Parliament, Bucharest, Romania

14. Beijing’s hutongs, China

North of The Forbidden City, the labyrinth of twisting grey alleyways and half-hidden courtyards that surround Houhai Lake make up the last major hutong district in Beijing. Once the home of princes, dukes and monks, these ancient backstreets are being torn down to make way for modern housing. For now, though, workers still scurry around on rusty bicycles and old men sit quietly in the shade, attending their caged birds, in what has become an ever-dwindling outpost of traditional Beijing.

Beijing’s hutongs, China

15. Bukchon Hanok Village, Seoul, South Korea

It’s strange to think that at the heart of one of the most densely populated places on the planet, just a stone’s throw away from the gleaming high-rises of bustling Insadong, there’s a quiet neighbourhood of traditional wooden houses, where locals chatter in tearooms and children play in the sloping streets. These charming hanokjip (literally, “Korean House”) hark back to a time when every home in Seoul had paper walls and was crowned with an elegantly tiled wing-tipped rooftop.

Bukchon Hanok Village, Seoul, South Korea

16. The Smithsonian, Washington DC, USA

The supersized collection of big-hitting museums and research facilities that constitute the Smithsonian spreads across a large swathe of Downtown D.C. The complex’s collection is so mind-bogglingly vast that if you were to spend a minute looking at every object on display, it would take you a hundred years to see everything – and that’s without stopping to sleep.

The Smithsonian, Washington DC, USA

17. Convento dei Cappuccini, Palermo, Italy

Warning: this is not one for the faint-hearted. Lining the catacombs deep beneath Palermo’s Convento dei Cappuccini, on the outskirts of the Sicilian capital, are the gruesomely preserved bodies of some eight thousand Palermitans, each one occupying its own niche within the jagged stone walls. The deceased were interred here up until the early 1880s, row upon row of them, dressed in their finest and suspended ad infinitum in some sort of grotesque waiting room for the afterlife.

Convento dei Cappuccini, Palermo, Italy

18. Islamic Cairo, Egypt

The medieval city at the heart of Cairo is a tangled web of narrow lanes, towering mosques and aromatic bazaars. Enter the warren at Khan al-Khalili, packed with goldsmiths, spice vendors and traders hawking incense, then burrow your way south to the Citadel, a hilltop bastion with majestic views over the district’s minaret-studded skyline.

Islamic Cairo, Egypt

19. Mumbai train station, India

At 8.30am at Churchgate Terminus, Mumbai, rush hour is in full swing. The trains pulling into platforms are swollen with suburban commuters, many of them carrying up to 3000 more people than they were designed to. When two trains empty onto a platform at the same time, disgorging their passengers in an explosion of colour, you need to stand still, take a deep breath and remember that there’s only another hour and half to go until things start to quieten down a little.

Mumbai train station, India

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