Suggest a place where one can go to study coral reefs, mangrove vegetation and estuaries.

Explanation

**Step-by-Step Solution:**

1. **Identify the Ecosystems to Study**: The question asks for a place to study three specific ecosystems: coral reefs, mangrove vegetation, and estuaries.

2. **Coral Reefs**: Coral reefs are typically found in coastal areas of deep seas and oceans. A notable location to study coral reefs is the **Andaman and Nicobar Islands**. These islands are known for their rich biodiversity and vibrant coral reefs.

3. **Mangrove Vegetation**: Mangroves are shrubs or small trees that thrive in coastal saline or brackish water environments. A prime location to study mangrove vegetation is the **Sunderbans**. The Sunderbans are famous for their extensive mangrove forests and unique ecosystem.

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