My search for a birthday gift led me to the real soul of Hong Kong

I've been drawn many times over the years to the vibrant duality of Hong Kong, where towering skyscrapers grow from forests like futuristic trees, double-decker buses rumble past clattering dim sum cafes, and barges glide across the harbour beneath rooftop cocktail bars.

This time, my trip to Hong Kong falls on my birthday but it'll be low-key. I haven't told anybody. Still, I've decided to treat myself to one particular present: an authentic mahjong set. The problem that I quickly discover, though, is there's a months-long wait for local handmade sets - and they cost much more than expected (I don't like myself THAT much). Which is how I've ended up here, my footsteps echoing on the concrete as I climb the stairs up to the fourth floor of an old dormitory-style building in the Central district.

The building (and its twin across the courtyard) is called PMQ for its former role as the Police Married Quarters where junior officers and their families lived from 1951 until 2000. Left vacant for years, it's now been turned into a creative hub, the old apartments filled with the workshops and boutique stores of young local artisans. It's one of the most interesting places to shop in Hong Kong, and where the Glocal Mahjong store sells me a fresh set of hand-painted tiles in a vintage briefcase.

More than just a birthday present, it's an apt symbol of this blend of old and new that I love about Hong Kong. Even deeper, though, I can also see the contrasts that I'm exploring on this trip in the suits painted on the tiles: stones, characters, bamboo and honours. From nature and adventure during the day, to culture and food in the evening. From the commercial centre of the main island, to the local neighbourhoods of the mainland. It's not hard to put together a winning combination.

"We call this the backyard of Hong Kong," John Lam shouts at me over the noise of the wind and the waves.

Bumping along on a speedboat, we're tracing the coastline of the Sai Kung peninsula, the easternmost point of the New Territories. With little development, the green mountains dotted by hikers and golden beaches launching kayakers do indeed look like a garden. But I've joined John's tour for its focus on stones, because this is also the heart of Hong Kong's UNESCO Global Geopark.

For two hours, we explore the enormous rock garden forged by volcanic activity. We float alongside a cliff of hexagonal stone columns, then turn a corner to find a huge arch shaped like the bell of a temple. I see a waterfall cascading from up high down towards deep sea caves, there are the "pineapple bun rocks" named for the local snacks they resemble, plus islands battered by the strong currents that also shake our boat at times. "Now we are in the Pacific Ocean," John shouts during a strong gust. It's quite a backyard!

But back on solid ground, I head along the pier, past the fishermen selling their catch directly from their small boats, to a small local cafe where, inspired by the rocks, I buy a warm pineapple bun. It actually contains no pineapple, the patterned crunchy topping just looks like one, but the soft buttery taste perfectly complements a coffee.

It's a simple traditional cafe, which fits with the atmosphere here in Sai Kung town. Once just a small fishing village with no road access until the 1970s, the town's attracted wealthier residents in recent years but still has very few high-rise buildings. Wandering the streets, it feels like a quaint coastal settlement. The busiest area is the strip of fresh seafood restaurants where I have crab and calamari before heading back to Kowloon.

On Kowloon's waterfront, smelling faintly of Victoria Harbour salt, Bruce Lee glares at me menacingly. Or rather, his bronze statue does. The martial arts star is an icon of the redeveloped Avenue of Stars (Hong Kong's Hollywood Walk of Fame), anchoring a modern promenade humming with crowds heading places like the K11 MUSEA shopping centre or Hong Kong Museum of Art.

Only 14 kilometres from the old Sai Kung fishing village, this district known as Tsim Sha Tsui feels worlds apart. There are a few heritage sights here, like the century-old clock tower and the Star Ferry Pier (first built in 1904), but most of what you find is new and sleek. Even the Former Marine Police Headquarters now houses luxury shops and fine dining in a complex called 1881 Heritage, with at least a nod to the past.

If you were to go about a kilometre deeper into Kowloon, you'd find the frenetic character of the markets around Yau Ma Tei, fake designer bags on one block, jade-inlaid jewellery on the next, exotic fruits across the road. A row of fortune tellers on the side of a park offer palm readings for about $27 or, for the starstruck, full astrology assessments for about $110.

But Tsim Sha Tsui is glitz, not grits. At sunset, I board the Aqua Luna, a gorgeous traditional-style junk boat, and settle into a sofa with a complimentary drink to cruise the water. "Wow, look at the oranges and the blues!" a local next to me exclaims. The sky is apparently not always this vivid.

But any night of the week, the neon signs on the skyscrapers are bright. I watch their colourful Chinese characters rapidly change while slowly eating dumplings and duck pancakes at Hutong, a restaurant 18 floors above Tsim Sha Tsui that serves northern Chinese cuisine. The dazzling electric screens sometimes even light up the handcrafted wooden ones in the restaurant, where the decor is inspired by Beijing's historic neighbourhoods.

Next morning, I follow the light across the harbour to Hong Kong Island and, trading the shoreline's concrete jungle for actual forest, rise up the mountains from their shadows. The dense tumult of skyscrapers is an iconic image, yet they cover just a fraction of the island. The rest is lush and verdant.

As I hike up through this greenery from Quarry Bay, figs lean over the path. Stopping briefly at the Woodside Biodiversity Education Centre, a small museum in a historic red-brick building, the exhibit tells me the forest is home to animals like pangolins, porcupines and civets. I won't spot any of them, but there's no shortage of wildlife. Walking higher, getting closer to scraping the sky myself, bird calls trill from the canopy and butterflies float in the humidity right in front of my face.

I've been joined on this hike by local guide Sidney Luk. About halfway, after two hours of uphill, we spot the Tai Tam Upper Reservoir. "It's green, like a piece of jade," Sidney reflects, reminding me of the market at Yau Ma Tei. We walk down, crossing the water along the bridge of the dam, stopping to take in the sweeping views down the valley beneath. "It's rare to have this kind of calm moment with no engines. Even if you climb up The Peak, you hear cars," Sidney tells me, referring to Hong Kong's most popular hike up Victoria Peak.

Descending towards our destination of Repulse Bay, we swap the sealed path for a jungle-like dirt track. A river runs down the mountain, creating little cascades, forcing us to rock-hop across. "You don't get this on Dragonback!" Sidney exclaims, now referring to Hong Kong's other most famous mountain hike. Indeed, I've done both those walks he's talking about and loved them, but hundreds of kilometres of hiking trails means constant new discoveries.

Late afternoon, I navigate its 16 preserved buildings, from the small Police Headquarters museum to the Barrack Block cafes, before going into the old prison cells themselves. Vietnamese leader Ho Chi Minh was jailed here in 1931 and famously journalled about the experience. "Hemmed in by towering, gloomy prison walls, he felt as though he was pacing at the bottom of a well," reads an information panel. It's much brighter now, and at the top of the complex, art galleries are a breath of fresh air.

Out the western entrance, onto the lively entertainment area of Staunton Street, I pop into a new bar called The Savory Project, where all the cocktails are... you guessed it, savoury not sweet (yet another Hong Kong duality). Drinks include Thai Beef Salad and Biryani, but I opt for Mala Punch, gin-based with ingredients like Sichuan pepper and fermented bean that hit me with a spicy edge and a hint of peat.

"It's always challenging creating drinks, so I just play with orthodox flavours and add in some unique ones," owner Ajit Gurung tells me as he starts making another.

There's a cosmopolitan crowd here tonight on the streets, moving between a mix of new cocktail bars, but that's pretty orthodox these days. Yet unique flavours are constantly being added - murals, arts centres, heritage revivals. Just 200 metres away, for example, is PMQ, where I earlier bought my mahjong set.

I think again about its symbols and how I can see this birthday journey across Hong Kong in its symbols. Does that mean there's something auspicious in those tiles? Maybe I'll find out one day... but first, I just need to learn how to play.

The writer was a guest of the Hong Kong Tourism Board