They were painted with these pretty bursts of colour thanks to the suggestion of one Donald Trump, who suggested locals pretty up the city for his 2004 Miss Universe pageant.
Back inside La Merced, the over-the-top decoration has nothing, thankfully, to do with Mr Trump.
Largely built in the 18th century after the original 16th-century church was almost destroyed in an earthquake, every inch of La Merced's interior is covered with pink and white swirls, resembling an intricately iced cake. The style is Mudejar, a Moorish art the Spanish brought to the New World in the 16th century.
La Merced was built to commemorate the many eruptions of Pichincha, the volcano that looms over the city and last covered it in ash as recently as 1999. The Virgin of La Merced is thought to protect the city from the ever-present threat of the volcano and locals pray to her in times of trouble.
A short stroll from La Merced lies San Francisco church and monastery, a grand complex built to complement the magnificence of Pichincha. Its multiple buildings and courtyards make it South America's largest religious complex and its museum houses an impressive collection of art, including a corridor of ornate and rather grisly religious statues - self-flagellation seems a favourite theme.
The almost 500-year-old church is in the midst of major restoration and when workers lifted the floor they uncovered a forgotten graveyard - catacomb after catacomb of human skeletons.
The benefits of restoration can be seen in La Compania de Jesus, an opulent church built by the Jesuits. Its incredibly detailed interior is covered almost entirely in gold leaf. It took the order from 1605 to 1765 to build La Compania, but just a couple of years after it was completed the Spanish expelled the Jesuits from South America. Today, after 18 years of restoration work, the church has been returned to its original glory and is perhaps the most striking in Quito.
Quito's historic centre was made a Unesco World Heritage site in 1978. According to Unesco, it's the largest, best-preserved and least-altered in Latin America. But despite its historic glories this part of town had a rough and tough reputation until a huge restoration and clean-up was undertaken 10 years ago. Today it's a lovely place to stay and, for tourists, perfectly located for easy access to the city sights.
It doesn't get any more central than the Hotel Plaza Grande, which sits right on the historic centre's Plaza de la Independencia (which the locals call the Plaza Grande). Originally the home of Juan Diaz de Hidalgo, one of the Spanish conquerors who founded Quito in the 1500s, the building became one of the city's first hotels in the 1940s. In 2005 it was renovated and restored into a luxury boutique hotel.
Heading into the highlands from Quito, the air thins with the increasing altitude and Kichwa - the mother tongue of most indigenous Ecuadoreans - is heard more and more often.
Following the winding roads up, the landscape changes to the windswept, bleak scenery of the paramo, or moorlands. The cosmopolitan Quitenos are replaced by the distinctive highlands people in their fedora hats; the women with long plaits and shawls, holding their babies on their backs. The ever-present wind here gives the people a weathered, ruddy look that seems to reflect the landscape.
Today men and women, boys and girls are all heading in one direction. It's market day, and along with their fedoras, the local women and girls are in intricate shawls, knee-high socks, dainty high heels and pleated skirts for the week's social highlight.
As far as markets go, Zumbahua doesn't get much better. As a visitor, it's hard not to feel like the stereotypical wide-eyed tourist, noseying among the locals as they go about their business. They're buying and selling an impressive array of fruit, brought up from the coast, plus animals (both live and dead), shawls, fedoras, palm sugar and more.
At one end, a mother and her son cook llapingachos - delicious flat corn and cheese fritters - while at the other, men mend clothes on ancient Singer sewing machines. People crowd around a shaman with strings of colourful beads and a microphone strung around his neck as he peddles his strange medicines.
Further up the road is Quilotoa lagoon, a magnificently blue volcanic crater lake encircled by high cliffs.
But after market the locals head home laden with bags and babies, walking the rocky path with ease; the children hopping along like mountain goats whipped by the cold wind. But at almost 4000m above sea level, we foreigners are puffing and panting almost immediately.
CHECKLIST
World Journeys has a range of Ecuador holidays available. Call 0800 117 311.
Getting there: LAN Airlines flies direct from Auckland to Santiago de Chile daily, with connecting flights to Quito. Fares start from $1839.
Where to stay: Hotel Plaza Grande, Garcia Moreno N5-16 and Chile Streets, Quito. Email info@plazagrandequito.com or phone +593 2251 0777
Alice Neville travelled to Ecuador with assistance from LAN Airlines and World Journeys.