Güler suffered a heart attack and was taken to the intensive care unit of Florence Hospital in Istanbul, where he breathed his last.
Dubbed "Eye of Istanbul", Güler rose to fame with his black and white portraits of the city.
He was suffering from kidney failure and had to be taken for treatment thrice a week.
"That dialysis makes me stupefied," he said in an interview with Anadolu Agency in 2015.
“I cannot do anything three days a week. It takes four hours each time, and it is unbearable.”
However, old age and illness did not stop him from pursuing his work.
In 2015, he took pictures of the ongoing construction of Istanbul’s third bridge on the Bosphorus.
Güler belonged to a family of Turkish intellectuals.
His mother came from an Armenian family which owned several houses around Beyoglu, a neighborhood in Istanbul.
Güler’s father was left an orphan at six years old. He was later a pharmacist for the Turkish army at the battle of Gallipoli in 1915.
Using his father's connections, Ara landed his first job as an assistant film projector in one of Beyoglu's many theaters.
In his father’s drugstore, where theater artists would gather regularly to buy make-up for plays, Güler met the founder of modern Turkish theater, Muhsin Ertugrul, and was even able to work with him.
“[Güler] always wanted to be a playwright,” wrote Nezih Tavlas in a 2003 biography on Guler called “Photo Journalist.”
At 22 years old, he received his first camera -- a Rolleicord II. His career as a photographer kicked off when he joined a local newspaper called Yeni Istanbul in 1950.
Güler met world-renowned French photojournalist Henri Cartier-Bresson through his connection with Romeo Martinez, editor-in-chief of Camera magazine, and became a member of Magnum Photos, an international photography cooperative.
By the end of the 1950s, he worked for world-renowned magazines such as Time and Life in the U.S., the French weekly Paris Match and Der Stern in Germany, traveling around the world from Pakistan to Kenya and from New Guinea to Borneo.
He was in Sudan in 1978 just before the second Eritrean civil war to report on clashes between rebel groups. Just before the 1980 military coup in Turkey, Güler went to Mongolia, the Turks' homeland, to photograph 8th century inscriptions. In 1990, he headed to Indonesia with his wife for a report on cannibal tribes.
But it was in Turkey that he made one of his most astounding discoveries: an ancient city called Aphrodisias in the western province of Aydin in 1958. As he was returning from a job involving the inauguration of a dam, his driver lost his way, ending up in a village where locals used the antique architecture as part of their daily life.
In 1957, he was in France covering the Cannes Film Festival. He met legendary figures from the film industry, including American filmmaker Orson Welles, Italian writer Alberto Moravia and Spanish artist Pablo Picasso.
Güler also photographed the likes of Winston Churchill, John Berger, Alfred Hitchcock and Salvador Dali, among many, many others.