Verne could write pure adventure stories, too, and didn’t need to put in scifi to make them work. I read this book multiple times as a kid and was utterly captivated by it. The vivid nature descriptions of Africa and South America, the young protagonist responsible for the crew, the strong and brutal depiction and condemnation of slavery … This book flinches away from very little. I still can tell you about the characters and the plot today, and it’s been nearly twenty years since I’ve read the book.
Plus, it’s responsible for teaching me what an entomologist is and does, so there’s that.