Mathura-Vrindavan: Krishna's Playground
मथुरा-वृंदावन: कृष्ण की लीलाभूमि
Quick Answer
Mathura is the birthplace of Lord Krishna and Vrindavan is where he spent his childhood. Together they form the most important Krishna pilgrimage, filled with temples, the Yamuna river, and an atmosphere of pure devotion that feels like nowhere else on Earth.