Renal pyramids lie in renal cortex/renal medulla.

Explanation

### Step-by-Step Solution:

1. **Understanding Renal Anatomy**: The kidneys are composed of two main regions: the renal cortex and the renal medulla. The renal cortex is the outer layer, while the renal medulla is the inner layer.

2. **Identifying Renal Pyramids**: Renal pyramids are cone-shaped structures located within the kidney. They play a crucial role in the urinary system.

3. **Function of Renal Pyramids**: The primary function of renal pyramids is to transport urine produced in the renal cortex to the renal calyces, which then lead to the ureter.

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