What geographical features are important for the growth of a civilisation?I know it needs to be near a water source and have fertile land, but I need another feature.
I would first add to or clarify the idea that civilizations need a water supply. Civilizations do need water, but that can come either from rivers that can be used for irrigation or from relatively predictable rains. Water is also important because it enables trade. In ancient times, it was very hard to move anything of any great size over land. Therefore, if you wanted to trade, you needed to next to the ocean and/or to a relatively large river. This means that there are a couple of different aspects to the idea that you need to be near water.
A second thing, according to Jared Diamond's book Guns, Germs, and Steel is that a civilization needs to be in a place where there are plants and animals that can be domesticated. There are plenty of places in the world with fertile land and water sources but few plants or animals that can be domesticated. The Mississippi River comes to mind as one such example. Diamond argues that civilizations sprang up in places where there were naturally-occurring plants and animals that could be domesticated and used to create agriculture. This agriculture led to civilization. This is a major reason why, to Diamond, civilization arose in places like the Fertile Crescent rather than in the Americas or Africa.
So, I would add that civilizations need the raw materials (plants and animals) that allow agriculture to arise.
The growth of a civilization can be ensured when there is a means for the inhabitants to defend themselves, such as being surrounded by mountains, having a safe harbor with a small entrance, or being high on a hill, overseeing the surrounding area.
A landscape that allows trade to flourish is also valuable. Location on an established trade route, access to a navigable sea or river route, any method of reaching other people and accessing new ideas and trade articles that give the inhabitants room for growth on a quality of life level.
Geography affects the weather as well, and in order for a civilization to attract new residents, farm their lands, or live their lives, there needs to be a mild weather abounding in the area.