Population density = Total population / Total area = 100,000,000 / 94,163 ≈ 1062 per km². Bihar has one of the highest population densities in India.

Raja Ram Mohan Roy, born in Bengal but deeply connected to Bihar through his work, is credited with founding the Brahmo Samaj, a major reform movement.

The Mahabodhi Temple is constructed primarily of bricks in the ancient Buddhist architectural style, dating back to the 5th-6th century. It is a UNESCO World Heritage Site.

Sher Shah Suri built the Shergarh fort as part of his fortification strategy. He was known for his administrative reforms and military architecture during his rule in the 16th century.

Nalanda University, founded in the 5th century CE in Bihar, was one of the world's oldest universities and was primarily dedicated to Buddhist studies, logic, and philosophy.

Sarnath is located near Varanasi in Uttar Pradesh, where Gautama Buddha preached his first sermon after attaining enlightenment at Bodh Gaya in Bihar.

Mahavira, the 24th Jain Tirthankar, attained nirvana at Pawapuri (also called Pava) in Bihar at the age of 72.

Vaishali was the capital of the Licchavi Republic and was part of the Vajji confederacy, making it an important republican center in ancient India.

Xuanzang (also known as Hiuen Tsang) visited Nalanda University in the 7th century CE during the reign of King Harsha and spent considerable time studying there.

The Didarganj Yakshi statue, a polished sandstone sculpture from the Mauryan period, is one of the most prized possessions of the Patna Museum.