According to Jain tradition, Bhagwan Mahavir observed several periods of deep meditation and fasting (known as Maskhaman, a fast without food and water for 48 hours or more) during his spiritual journey. The parna is the ritual breaking of the fast.

Regarding the fourth Maskhaman parna place of Bhagwan Mahavir:

• Location: The fourth parna of Maskhaman by Bhagwan Mahavir is traditionally believed to have taken place at Champapuri (also known as Champa), which is an ancient city near present-day Bhagalpur in Bihar, India.
• Significance: Champapuri is an important site in Jain history, closely associated with both Bhagwan Mahavir and earlier Tirthankaras.

References:

• "Bhagwan Mahavir: Life and Philosophy" by Dr. Kailash Chand Jain
• "Mahavir Swami: Life and Teachings" by Dr. H. L. Jain

If you need information on other parna places or details about Maskhaman, feel free to ask!