There is nothing much to see other than the old cannon , and a panoramic view of the landscape beneath it.
The trek is through a unpaved trail.
From an anti-piracy and military standpoint point, the island remained a strategic point, especially when Mumbai was gradually made into a busy port city in the subsequent centuries. You can still see a few cannon outposts at a place called the Cannon Hills in Elephanta.
Trail to Cannon Hill in Elephanta Island