There are many forts in Maharashtra that are very difficult to climb. Although difficulty level depends on a person but considering the expertise needed, total time for the trek and different activities involved for the trek, I am giving my opinion. One of the hardest treks in Maharashtra would be Lingana fort trek. Even regular trekkers consider it as a challenging trek. Lingana is a massive pinnacle. There were rock-cut steps to go to the fort. Unfortunately, these steps are destroyed now that makes Lingana fort almost inaccessible. There are other toughest treks in Maharashtra such as AMK fort trek, Salher fort trek, Bhairavgad trek, etc. Read more: http://bestindiantreks.com/toughest-most-difficult-treks-in-maharashtra/