Piranesi by Susanna Clarke. I didn't read much of it. I hated the writing style, I didn't understand the story, I didn't understand who the characters are...just a big NOPE from me.
I'm currently reading Yesteryear by Caro Claire Burke. Not loving it so far - not sure I'll be able to continue with it. I hate the writing style, and I hate the main character, Natalie.
I somehow, and miraculously, managed to read The Correspondent by Virginia Evans, but it was far from being my favourite book. I liked the letter-format of writing, but I didn't like the main character, Sybil, at ALL - and I hated that so many of her letters were her reminiscing her past. I generally don't enjoyreading about people's past and memories - neither in books or in TV series and films.
Some years ago I tried to read Blue Mind by Wallace Nichols. It's not a Fiction book, but I'm interested in water science so thought it would be an interesting book to read. It had some facinating points, but he waffles too much, and repeats points, which made me not finish the book.