Historically, Bengaluru was built around an ingenious, interconnected network of man-made lakes (keres) designed to capture monsoon runoff, as the city lacks a major perennial river.
* **Prominent Lakes:** Ulsoor Lake (boating and recreation), Sankey Tank, Yediyur Lake, and Agara Lake serve as critical ecological zones and public walking spaces. * **Ecological Challenges:** Larger water bodies like Bellandur and Varthur lakes have faced severe pollution and encroachment due to rapid urbanization, though extensive citizen-led and governmental rejuvenation efforts are currently underway to restore them. * **Vrishabhavathi River:** Once a pristine tributary of the Arkavathi, it now serves largely as an urban drainage channel, highlighting the city's complex relationship with water management.