A small brown dog wearing a faded pink T-shirt jogged down a dirt street. I decided to follow him. He seemed as good a guide as any. He was in no rush, stopping to sniff the flip-flopped feet of the fat brown girls who sat gossiping on doorsteps, rocking babies, their tight, skimpy vests revealing cleavage you could lose an arm in.

The dog took me down the narrow back streets of Old Havana, where faded pastel paint peeled from the façades of elderly buildings. White sheets and blue shirts were strung up to dry over the twisted stumps of wrought-iron balconies; women leant over crumbling carved stone balustrades and shouted to their children in the street. These once pristine and exclusive colonial mansions quietly decay while life inside them thrives. Here lies the beauty of Habana Vieja, evident in her decline.

My guide stopped; his ears pricked, as he spotted a man in torn denim shorts with a thick gold chain around his neck. The man wiped sweat from his armpits with a handkerchief and shouted up at a window high above the street. A woman with curlers in her hair leant out of the window and lowered a wicker basket on a piece of rope. The man took his pizza out of the basket, replaced it with a bank note and the basket was raised again.

A gang of kids with skinny legs and grubby T-shirts had set up a baseball pitch at a crossroads, each pavement corner representing a base. I stopped to let them pitch. "Hey beautiful lady," called a small boy, smiling mischievously at me as he threw a small coconut. Another boy hit the makeshift ball expertly with a stick. The dog caught the ball in its mouth. The children shouted. The dog ran. I was guideless once again.

The uneven dirt streets gave way abruptly to newly laid cobbles and opened out on to Plaza Catedral. The limestone cathedral was weathered by centuries of hurricanes. Fossilised sea-creatures were embedded in its walls, as though the building itself had risen, fully formed, from the sea. Waistcoated waiters served overpriced mojitos to tourists wearing Che Guevara T-shirts, expensive cameras slung around their necks. A brass band played "Guantanamera". Ancient black ladies with their life stories etched on their faces wore gaudy satin flamenco dresses and flowers in their hair. They posed for the tourists, huge Cuban cigars dangling, unlit, from their lips.

I bought an ice cream from the ground-floor window of someone's house and rested on a bench. A good-looking young man sat down next to me and asked where I was from. We talked, he in broken English, I in tentative Spanish. Suddenly, he stood up. I turned and saw a policeman standing silently nearby, arms across his chest, staring at the man as he walked away.

The Caribbean sun began to lose its heat. I sat outside on the terrace of a hotel bar. The staff looked bored and tired. The bar was empty, except for Yamila. She was a beautiful mulatta with waist-length hair and daring eyes. She told me she was learning English, that she wanted to travel. An overweight tourist with grey hair and a pink silk shirt sat down at the bar and ordered a cocktail. Yamila excused herself and went over to him.

I gazed at the ferries crossing Havana bay while the sea turned orange, then grey. When I could no longer make out the white star of the Cuban flag that fluttered above the ferry terminal, Yamila reappeared with flushed cheeks and tousled hair. "Vamos," she said, offering me her hand.

She took me to the Malecon. Sweeping around the northern edge of the city, the Malecon's protective wall shelters Havana from the sea. Locals sat hip to hip along the wall, playing music, fishing, dancing, swapping stories, sharing worries, selling peanuts, looking north across the sea.

Yamila's friends were waiting. We drank rum and watched the lights of Havana rippling in the stinking black water below the wall. "You must be hungry," said Yamila.

A boy was sitting on the wall next to us, his pole in the water, two unidentifiable fish by his side. Yamila gave the boy a peso and walked away with the fish. She returned 10 minutes later carrying freshly fried fish and some rice on the lid of a cardboard box.

She took her ID card from her purse and showed it to me, proudly pointing out her photo, her name, her date of birth, explaining that Cubans must carry this card with them at all times. Laughing, she cut a slice of fish with the edge of the card and scooped it up along with some rice. Nodding encouragement and grinning, she offered it to me.

This year's prize winners

And the winner is ... Kate Megeary, a 32-year-old London resident who is no travel novice. A tour leader for the adventure travel company Explore, Kate read anthropology at university and has always been a globetrotter. A Spanish speaker, she is naturally drawn to Latin America although her next trip is to Mallorca. The first prize takes her out of her Spanish-speaking comfort zone but she says she's "thrilled" about taking her awarded trip (provided by bmi and Regent Holidays) to the Central Asian republic of Kyrgyzstan.

The winner of the unpublished writer award is Neil Matthews for his article about Berlin entitled "Memories in Blue". Neil hasn't been published before but co-edits 'Travel with Mensans', an anthology of travel writing by Mensa members. Neil wins a travel writing course with Travellers' Tales.

The contest was closely fought and the runners-up – Tom Bird, Lucy Clark, Emily Sharratt and Liz Sillars – win three Bradt travel guides.