Steeped in centuries of history, India’s capital is dotted with the impressive monuments left by successive waves of conquerors. The most prominent are the 17th-century Mughal Red Fort and those of the British imperial city of New Delhi. The latter includes Sir Edwin Lutyens’ majestic Rajpath, an immense ceremonial avenue that leads up to the Presidential Palace and Parliament buildings. Delhi today is a vibrant city, but it is struggling with chronic air pollution and congestion.