It is a quiet, misty December morning in Urubumba, an unembellished town at the rustic foothills of Sacred Valley, Peru. Dark clouds obscure the snow- capped peak of the majestic Ch'iqun mountain and cast a shadow over the usually busy town centre. Rain pelts the cobbled streets, which are draining of pedestrians rushing to seek shelter.

My husband and I are in the Peruvian Andes to visit mountain towns and ruins, notably the renowned Machu Picchu or "lost city of the Incas".

An unexpected throng of children crowds an unsheltered pavement. Holding empty plastic mugs, they stand resolute by the decrepit grey stone walls, as though in cheerful defiance of the bleak weather. Our guide Jose, who is walking ahead, spins around.

"A chocolatada," he gestures delightedly.

I have read about the tradition but never witnessed one. Chocolatadas are a defining Peruvian feature in the lead-up to Christmas, when organisations and businesses prepare hot chocolate (locally known as chocolate caliente), sweet breads and toys for less privileged children in their community.

Throughout December, children from mountainous communities descend in droves for a slice of the action in the Sacred Valley and Cusco - the ancient capital of the Inca empire - where numerous chocolatadas are known to occur.

"In Peru, it is not Christmas without hot chocolate," Jose says. "And when you see chocolatadas all around, you know that Christmas is coming."

Chocolatadas, coupled with the bustling festive market in Cusco on Christmas Eve, as we will soon discover, are distinct highlights of Christmas in Andean Peru. Intrigued, we don our rain ponchos. Jose speaks to the lean, tanned shopkeeper in a blend of Spanish and Quecha, the indigenous language of the Andes.

The children are swiftly shown into the shop, where racks of provisions have been judiciously shoved aside. A rosy-cheeked baby, worn on her mother's back with a manta, a Peruvian wrap with a hardy weave, flashes me a toothless grin. The storekeeper's wife, whose raven hair hangs down her crimson cardigan in taut double braids, is conscientiously stirring an enormous vat of piping-hot chocolate caliente.

In Andean Peru, the brew is made from scratch by melting pure cacao paste - largely sourced from Quillabamba, six hours from Cusco - in water with spices and heaps of sugar. We are told that chocolate was known only as a drink for a long time in Peru, and hot chocolate is an ancient tradition here.

The inviting aroma of cocoa, cloves and cinnamon wafts through the air. The scent is especially comforting in this cool December season fraught with spotty thunderstorms, and it is not difficult to see why hot chocolate is enshrined as a Christmas custom.

A small but sprightly silver- haired lady, whose face creases deeply as she smiles, speaks kindly in Quecha to the children, whom I estimate to total around 90.

"She is trying to lift their spirits while they wait. They will sing a song," Jose translates.

A chorus of guileless voices, high-pitched and lilting, eclipses the beating of rain at the window. The children sing neither in harmony nor at the same tempo, but the moment is emotive.

"This is a common Christmas villancico sung in Quecha," Jose tells us. "The children may come from different communities, but they know the same carols."

Christmas villancicos are poetic, folkloric songs introduced to Latin America by Spanish conquistadores in the 16th century and now sung in the native vernacular.

The storekeeper's wife waves the first child over, and gingerly ladles chocolate caliente into his mug. The boy, who looks to be around seven years old, sips his rich beverage, his eyes aglow with pleasure. My eyes tail him as he receives some bizcocho, or Peruvian sweet bread, that the elderly woman is slicing.

The storekeeper fishes out a canary-yellow toy truck. The boy exclaims gleefully to his friends, brandishing the gift in one hand and balancing bizcocho on his mug with the other.

"They are so happy," Jose says, before offering to scoop hot chocolate to hasten the process. "For many of these children, this will be the only new item they get the whole year."

Every child goes through the stations, and the entire operation takes nearly an hour. It gets chaotic, but the mood is never dampened and the atmosphere is punctuated with squeals of joy.

The rain is abating to a very light drizzle now, and I crouch outside to the eye level of a doe-eyed girl who is chomping down her bread-roll. I speak neither Spanish nor Quecha, and can only clumsily communicate with a thumbs-up signal. She returns my greeting with a resplendent smile. The girl runs to her mother who is leaning against the walls, resting her eyes and holding a sleeping toddler in her arms.

"Some of them camped out here since last night," Jose tells us later. "Once they hear of chocolatadas happening this Christmas week, they come early to wait."

"I have a daughter," Jose adds, explaining his partiality towards chocolatadas. "I can buy her new things and hot chocolate for Christmas. Not everyone here is so blessed."

It is no long-term solution to poverty, but he explains that for Peruvians, there is no more fitting time than Christmas to do something for the less fortunate, and the chocolatada - using the ancient tradition of hot chocolate - is an expression of love and solidarity.

The children disperse. Some return to their mothers while others walk into the distance, chattering elatedly, grasping toys and empty mugs.

The unbridled excitement of both children and adults is infectious. How fascinating that a simple yet compassionate affair can powerfully evoke the sometimes-elusive Christmas feeling, my husband remarks.

As we drive through a road that parallels the revered Urubumba River, I consider how the chocolatada tradition embodies the Christmas spirit of giving.

It is two days to Christmas, but it feels like Christmas has come early.

CHRISTMAS EVE IN CUSCO

On Christmas Eve, we discover why the Santurantikuy market at Plaza de Armas is considered the pinnacle of all Christmas festivities in Cusco.

Here, the main celebrations do not happen on Christmas itself, but on Christmas Eve, leading up to "la noche Buena" (the good night), when people gather at the square.

Santurantikuy, which means "selling of the saints", is the largest art and craft fair in the region, and a testament to the distinctive nature of Christmas in Andean Peru.

The plaza is a wild flurry of activity. Hundreds of artisans from surrounding regions, even as distant as Bolivia, flock here to sell handicrafts meant for nacimientos - nativity scenes - traditionally assembled at home on Christmas Eve.

Peruvian families comb the market to locate the best ornaments for their nativity scenes, even miniature clothes for its characters. "Here, creating a nativity scene is like the Western tradition of decorating a Christmas tree," a local later tells us.

A nativity scene in a Peruvian home comprises a rectangular wooden structure that houses earthen figurines of Mary, Joseph and farm animals surrounding an empty manger. At the stroke of midnight, the figure of Nino Manuelito will be deferentially placed in the manger.

Beyond the hodgepodge of crafts and plants, nothing spells a festive market more than food. The cold air is thick with the appetising scent of roast meats and corn on the cob. Popular treats include the anticuchos, or beef hearts marinated in vinegar, cumin, salt and pepper, then sold on a skewer with a potato; and the chicharon, braised pork rolls fried in their own fat.

Children are merrily slurping the customary spiced chocolate, and adults guzzling ponche, a sweet rum, to warm themselves on the frosty evening.

Christmas Eve is a particularly beautiful time to be in Cusco, located 3,400m above sea level, and the gateway to exploring Machu Picchu and the Sacred Valley. Surrounded by colonial stone arcades and flanked by two spectacular cathedrals, Plaza de Armas is transformed into a festive wonderland with twinkling Christmas lights, many in the shapes of animals.

"Reindeer," I say of the lit silhouettes, thinking they are like typical Christmas decorations back home.

"Look again," my husband responds. I realise that the shapes are of llamas and alpacas, animals native to the Andean mountains.

It hits me that Andean Peruvians related extremely well with the pastoral element of the nativity story, in which baby Jesus was born in a stable. Today, Christmas is evidently a highly important festival, with characteristics unique to the Andes.

The huge turquoise doors of the stunning Santo Domingo cathedral are heaved open for a grand evening mass, Misa de Gallo. At midnight, a cacophony of fireworks explodes through Cusco and other Peruvian cities, igniting the skies with blazes of flashing colour.

It is a boisterous welcome to Christmas, and a mark after which Peruvians take their celebrations indoors. Christmas family dinners begin, typically serving hearty menus of turkey infused with pisco (a local grape spirit), cuy (roast guinea pig), chicken soup and paneton (an Italian sweet bread with candied fruit, wildly popular in Latin America). Gift exchanges and dancing follow, often into the wee hours of the morning.

In contrast to the rousing festivities on Christmas Eve, Cusco is typically deserted the next day. Christmas morning is serene, and the streets are largely clear in an unusual lull.

Most businesses are closed, as locals spend the day with families at home. An English backpacking couple, with maps in hand, walks past us. We smile and exchange season's greetings.

It is another foggy day in the mountains. We are introspective, thankful for the lovely buildup to Christmas and silently reflecting on what the day means to us.

Slowly, we make our way to the legendary Machu Picchu, which is dreamily swathed in clouds today.

Denise Lim is a freelance writer.

A chocolatada trek

Conditions are sparse. Straw- roofed huts made of mud brick spot the desolate landscape, where there are more alpacas than humans. There are no electricity and conveniences.

To brew hot chocolate, participants use peat, blowpipes and matches to start fires the timehonoured way. Children from the village are clothed in daily traditional attire - polleras (wide skirts) and monteras (structured hats) for girls; ponchos and chullos (knitted hats) for boys. In the rugged terrain, they eagerly await hot chocolate, paneton and toys.

This setting is the highlight of a trek organised by adventure travel specialist Apus Peru (www.apus-peru.com), which delivers the chocolatada tradition to a remote village high in the mountains in December.

Chaullacocha, situated 4,200m above sea level in the Lares region, is typical of small communities scattered through the Andes, with lifestyles that few tourists will encounter.

The chocolatada trek follows a popular trekking route to Machu Picchu, with an added day hiking to Chaullacocha for the event. The journey is off the beaten path. Apus Peru, which started the trek in 2010, has taken just 30 travellers to Chaullacocha since its inception.

Ariana Svenson, co-founder of Apus Peru, says that the day of the chocolatada trek is usually long and tiring. Conditions can be wet and cold in December. Snow is also a possibility, adding challenge to the hike.

The trek is not for everyone, but tempered with the right expectations, it might end up being the most authentic and memorable part of a trip.