Geographical features are divided into two options - natural or man made. They are large features you might see anywhere on Earth, for example the largest mountain in the world, Mount Everest, is a geographical feature. The Pacific Ocean is a geographical feature. Any volcano e.g. Mount Etna would be the same, then there's the Sahara Desert and so on.
A man made geographical feature could be the Norfolk Broads in the UK, a massive waterway that was dug a few thousand years ago when the area was full of peat. Man dug out the peat to use for burning fires and gradually the areas filled with water and became waterways that are now used for leisure sailing.