The oldest civilization of India was discovered accidentally. Kiln baked bricks found during mid 1800 by the British engineers aroused the curiosity of the archaeologists of the next century (in 1920). The bricks found while construction of railway lines at the location between Punjab and Karachi were found to be more than 5000 years old. Soon the ancient cities of Mohenjodaro and Harappa were discovered. These cities were once part of one of the oldest civilizations of the world – the Indus Civilization.