Round Island is situated in the sheltered western portion of Poole Harbour. The pier faces west towards the R.S.P.B. Reserve on the Arne Headland and views from around the island include the Purbeck Hills and Corfe Castle.
The Island is approximately 15 acres in size with a path which winds through rhododendrons and woodland which is suitable for pushchairs and wheelchairs. There is a small sandy beach with shallow water which is very safe for children.