Ganesh Gufa, nestled in Mana village in Chamoli district, is a place of mythological and historical importance. This naturally formed cave is a marvel in itself, which draws the attention of many globetrotters. Within the proximity of Ganesha Cave is another famous cavern called Vyas Gufa, which can be visited.
Although being small in size, Ganesha Gufa has great religious significance as it is associated with a famous Hindu legend which states that when sage Vyas was composing the Mahabharata, he needed someone to note the verses that he was dictating.
To this end he approached Ganesha worshipped as the “God of Wisdom”. The Lord agreed to it but only on one condition. It was that Ved Vyas should not stop dictating for a moment or else he will stop writing and leave. Maharishi Vyas agreed to it, telling Ganesha not to write anything on his own or without discussing with him. Sage Vyas narrated the legend as fast as he could.
When Ganesha pressed on the texts to keep up with the pace, his reed pen broke. However, this did not stop Ganesha from writing, so he continued the task by breaking a part of his tusk to be used as a pen. Finally, the epic Mahabharata was created by Ved Vyas which was etched by Lord Ganesha in this tiny cave.
Source:
https://bugyalvalley.com/uttarakhand-tourism/chamoli/ganesh-gufa/