Bogota is at its most colourful on a Sunday morning. Once a week, city highways are closed to motorised traffic and transformed into a blur of fluorescent lycra as thousands of cyclists, children on tricycles and teenagers on rollerblades whoosh past. This motley Tour de France passes under the stem gaze of Simon Bolivar, the liberator of South America, whose statue presides over the main square. They steer under the bell towers of the two-century-old cathedral, where the last hymns of morning mass reverberate inside, congregations in their Sunday best stepping out into the Andean sunshine. They pedal past the market at Paloquemao, where weekend shoppers wander among roses, sunflowers and lilies, flowers that only hours before were snipped from the surrounding countryside, soon to decorate weddings, funerals, birthday parties and dinner dates across the capital.

Not so long ago, Bogota was a city in the same league as Mogadishu, Baghdad and Lagos – synonymous with drug cartels, crime and terrorism It was a place where no sane tourist ventured and few residents would potter between neighbourhoods on a Sunday stroll. Bogota’s problems are far from fixed, but safety has improved and one of South America’s liveliest cities is blooming. Former no-go areas are now sewed by cycle superhighways; streets once avoided because of drive-by shootings, no w busy with artisan coffee shops.

The face of the city is constantly changing, especially just after Sunday lunchtime, when security guards are taking a siesta and Bogota’s street artists are often at work. Just over a decade ago, local authorities in Bogota took steps to partially decriminalise graffiti, with some hoping to reverse urban decay by transforming neighbourhoods into open-air galleries. Today, like almost no other city in the world, artworks can be found on almost every surface in Bogota. Some are legal, some not quite so legal. Some are vast murals of Colombian landscapes commissioned by corporations; some are very small – little stencils of cats and dogs sitting patiently on street comers.

‘Street art is a celebration of our culture’, explains artist Ecksuno (real name Juan Sebastian Garcia), embarking on a graffiti tour of the city. ‘Colombia has so much variety to inspire us, it is almost like a collection of different countries, each with its own styles and colours.’ Bogota’s street art can be a way to gauge Colombia’s political temperature, Juan points to murals advocating rights for indigenous communities, others protesting against deforestation of the Amazon, And it works as a helpful introduction to the country’s natural and cultural riches, too, Juan points to one of his own creations: the frozen peaks of the Sierra Nevada on the country’s Caribbean coast, rising over a sunny plaza where families are taking Sunday picnics.

‘In Bogota there is a particular quality to the light,’ says Juan. ‘We are high up in the Andes. Somehow the clouds don’t feel very far away, and wherever we go in the city we have the mountain watching over us.’ The mountain in question is Monserrate – Bogota’s urban peak, like Corcovado in Rio de Janeiro or Arthur’s Seat in Edinburgh, It is a Sunday afternoon tradition for pilgrims to climb the 1,500 steps to the church on the summit (everyone else cheats and takes the cable car or the funicular). Ascending to 3,152m above sea level, the smog recedes and the colours of the city become more intense still. There is the deep-blue dome of the sky, the bright orange of the cable car. And beyond the city rises a range of green hills, on whose slopes roses and sunflowers grow for the Sunday market.