The title of "the oldest restaurant in the world" has always been a hot debate since the Guinness Book of Records placed Sobrino de Botín as the longstanding resto. Many restaurants have come afoot and contested that idea, leaving the people now with the question, "What is really the oldest restaurant in the world?"

Sobrino de Botín is located in Madrid, and it is what people considered as your typical wooden Spanish building with four floors, consisting of the cellar and restaurant. It was founded in 1725 by a Frenchman named Jean Botin and his wife who called the restaurant Casa Botín. Their nephew succeeded the restaurant and renamed it to Sobrino de Botín, which means 'nephew of Botin."

Is this truly the oldest restaurant? Here are five contenders for the said title.

St. Peter Stiftskeller in Salzburg, Austria. There's a document mentioned by the scholar Alcuin in 803 AD believing it to be the world's oldest restaurant. However, historians say, they do not possess legal papers to prove they're the oldest in the world. Stiftskeller, however, do holds the title of the oldest restaurant in Europe, if they cannot claim the global recognition. And, if not in 803 AD, the restaurant entered history books by the 1300s. This still makes it quite old.

Biànyífāng in Beijing. This is China's original duck restaurant which has been existing back to the reign of the Qing emperor Xianfeng in 1416. Many locals and tourists dropped by for a taste of roasted duck cooked in a closed oven style called mènlú.

Zum Franziskaner, Stockholm, Sweden. The Art Nouveau restaurant was built in 1421 during the reign of King Erik of Pomerania. They moved to Österlånggatan in 1520, then a century later at their current address, Skeppsbron 44. People often come here for the beer.

Honke Owariya in Kyoto, Japan. This house of ramen first opened as a small confectionary shop in 1465. Perhaps their most famous dish is the soba buckwheat noodles which are still what most travelers look for after 500 years.

La Tour d'Argent, France. People question whether the restaurant had indeed opened in 1582 because the place does not offer any papers to prove its claim. It has gone so many challenges which include losing two Michelin stars over the years. However, when Disney-Pixar aired Ratatouille, where Gusteau's restaurant was inspired from La Tour d'Argent, the restaurant suddenly boosted its sales and fame once more.