Dubbed the "Blue City", Jodhpur is the second largest metropolis in the Indian desert state of Rajasthan. Joining an arsenal of colourful neighbours - the White City (Udaipur), the Orange City (Nagpur) and the Pink City (Jaipur) among others - the Blue City is best observed from mighty Mehrangarh fort, which towers over the indigo enclave. It is unclear why locals began painting their buildings in this colour. One theory suggests Brahmins - the priestly class at the top of the caste hierarchy - wished to indicate their caste-instigated traditions. Another suggestion - the blue wash is simply a means of combating termites and other insects. It may also have been applied in order to keep structures cool.

Known colloquially as "The Big Hole", this local Samoan swimming spot in the South Pacific is quite possibly one of the most unusual places to swim on the planet. A natural wonder, the Sua Ocean Trench was formed during an ancient lava eruption and consists of two large holes joined by a lava tube cave. The 30-metre, almost perfectly symmetrical swimming hole is surrounded by lush vegetation and filled with seawater, connected to the ocean by an underwater cave. The only access into the secluded and sparkling blue waters is via a single ladder with a small sitting/viewing platform at its base.

Yves Saint Laurent said: "A visit to Marrakech was a great shock to me. This city taught me colour". The late couturier came to the North African city in the 1960s and in 1980 bought an abandoned property and former palm grove on the outskirts of town. The property was originally owned and designed by the French Artist Jacques Majorelle. With a passion for botany, Majorelle created a garden made up of exotic plants and rare species - including cacti, water lilies, palms and bamboo - gathered on his travels. In 1937 the artist created an ultramarine blue known today as Majorelle blue, and used it to paint the garden, which he opened to the public in 1947. The gardens remain open, and blue, to this day.

An island shaped like a wonky croissant is heaven enough for us, but Oia's treats don't end there. Photogenic for its romantic sunsets, iconic caldera and cliff-top whitewashed villages, Santorini's star is the ultimate Greek Island village. Converted peasant houses complete with blue shutters are etched along the island, complimenting the surrounding expanse of oceanic blue. The Church of Anastasis in Imerovigli is the blue-hued cherry on top.

Tucked high in Morocco's Rif Mountains, Chefchaouen - known as the Blue Pearl of Morocco - is so-called for its blue-rinse houses and mosques. In contrast to Morocco's primarily terracotta terrain, each year the town is washed with a new coat of blue paint, a custom which dates back to the 15th century. Jewish refugees fleeing the Spanish Inquisition settled in large numbers in Chefchaouen, bringing with them their tradition of painting things blue to mirror the sky and remind them of God.

Canadians are known for their sunny-side-up disposition but their lakes remain oh-so blue. Joffre Lakes gleam with a bright blue opaqueness - the result of a glacial silt suspended in the water. The particles dance with the sun's light and makes the water appear bright green and blue in colour. Enveloped by the Matier Glacier, keen hikers can set this as their endpoint. From mountaineering to camping, wildlife viewing to fishing, it's all par for the course here.

Known as the Blue Mosque because of the tiles used to decorate the walls of its interior, this historic religious complex is overwhelming in both size and design. Architect Sedefkâr Mehmed Ağa combined Byzantine Christian and traditional Islamic architectural elements to create the masterpiece. Lined by more than 20,000 handmade turquoise İznik tiles, the building's upper levels are also painted blue with natural light flooding in from more than 250 stained glass windows.

An underwater sinkhole of the deepest blue, The Great Blue Hole of Belize is almost dreamlike in appearance. Believed to be Earth's largest in area, forming a perfect 1000ft-diameter circle on the surface, the Great Blue Hole forms part of the Lighthouse Reef. The navy blue pupil with an aquamarine border is estimated to be 430ft deep, yet ds are decidedly short, lasting a mere eight minutes. Still, with more than 100 types of coral and some 500 species of tropical fish, the experience is sure to scintillate.

You've no doubt seen the viral Pinterest image of glass igloos dotted in the middle of an isolating snowscape. Located in the Finnish wilderness, Kakslauttanen is a year-round resort (closed only for the month of May) in Lapland, 250km north of the Arctic Circle. The Northern Lights are the priority here and the resort is right in the zone for optimal aurora viewing. Accommodation ranges from wooden chalets to glass igloos. Considering how often excursions to see the Lights are non-starters, catching them from the comfort of your own bedroom is pretty appealing and will save you the disappointing bus ride home.