Which hills have the nickname "blue mountains"?

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South India's Western Ghats are home to the Nilgiri Mountains, often known as the Blue Hills. They are rich in tea and coffee plantations, earning their name from their bluish tint. Ooty, a South Indian hill station located in the Nilgiris, is referred to as the "Queen of Hills." It is a well-liked tourist area with gently sloping hills all around, a central lake, and a healthy RL climate.