Another old one is 'The War of the Worlds'. It was significant because it was one of the first to depict an alien invasion. This was a new and exciting concept at the time. It also showed how humans might react in the face of a much more technologically advanced enemy. It was so well - written that it has been adapted many times, showing its lasting influence on the science fiction genre.
Sure. 'Frankenstein' is one of the oldest. It's significant because it was one of the first to really delve into the idea of science creating something that could have unforeseen and often terrifying consequences. It made people think about the limits of scientific progress.
The works of Jules Verne like 'A Journey to the Center of the Earth' are important old science fiction books. His books were significant as they took readers to places they could never actually go in real life, whether it was deep underground or far under the sea. They sparked the imagination of generations about the possibilities of exploration and discovery. His detailed descriptions made the impossible seem almost real. And 'The Time Machine' by H.G. Wells is also very old. It was important as it introduced a whole new concept of time travel, which has been a staple in science fiction ever since. It made people think about the nature of time and the future and past in a way they hadn't before.