It is immediately to the east of Boulter's Island, separated by the former millstream.
The island is now a park administered by the Royal Borough of Windsor and Maidenhead.
Boulter's weir runs from the top end of the island across to the east bank near Taplow.
A kayak flume has been built adjacent to the weir on the island.
For over 20 years until it was stolen in October 2011, the island housed The Companion, a memorial statue for four local schoolboys who died in a skiing accident.