Acknowledging there were "far worst things happening in the world", Ms Warne told her 1.7 million followers she was sharing her experience as "many of you look to my account as a travel guide and may book places as a result".
"For me, this place was the worst dining experience I have ever had," she said of the restaurant, which offers sweeping views of the Mediterranean Sea.
She said she had attended with a friend.
"We were so excited a table was available during our dates and even after reading the mixed reviews we decided to try it anyway as we saw it as a once-in-a-lifetime experience.
"I gave them my list of food requirements when I made a reservation three months in advance.
"But as soon as we sat down we were told the kitchen had not and could not prepare anything not on the set menu.
"I am used to not being able to eat most options on a menu but as this was a "fine dining experience" and they asked for my food requirements well in advance, I was frustrated to hear I would still need to pay 180 euros ($300) for the set menu, much of which I could not eat."
She said the only things she could eat from the menu were some beans, two pieces of vegetables and a fruit plate for dessert. Her friend, who could eat everything, said the food was "underwhelming" anyway.
"We are no food critics, but this food seemed to fall victim to a fancy restaurant trying to create fancy food but completely missing the mark and offering bizarre and confusing food as a result," Ms Warne continued.
"For me this place is not worth the money even despite the fantastic view.
"The customer service was terrible, and I was further disappointed when the staff and the chef would not acknowledge the situation."
She praised the "beautiful" setting but recommended her followers go to a cheaper local restaurant and ordering the "15 euro [$26] mouth-watering pasta" instead.
In another post, which featured a photo of the restaurant, she said the food was "truly awful".
Many followers responded positively to Ms Warne's review, with some who had visited the restaurant agreeing it was "completely underwhelming" and she had "hit the nail on the head". Others branded the restaurant's treatment of Ms Warne as "garbage" and thanked her for her "honest review".
But others criticised Ms Warne for so publicly slamming the eatery — including TV host and travel expert Catriona Rowntree.
"So why bother posting and being negative? Just so you can show the shot? What's the point?" the Getaway host said.
"Is all that really necessary? You must know that it paints you into a corner which is less than favourable," someone else said.
"You literally have an intolerance to every kind of Italian food ingredient, I don't think this is a fair review," another reply read.
"Did you took into account that perhaps they are human beings too and they feel pretty tired of all the peak season crowd and all their selfishness?" someone else wrote. "I love your feed Nicole but not your 'wanna be TripAdvisor' new vibes."
