Cramond Island is a tidal island lying just off the mainland in the Firth of Forth. The island can only be accessed at low tide and the tide comes in deceptively fast. Times are posted at the start of the causeway so be sure to check the times or you might end up having to spend an unscheduled night on the island.
If you do get stuck, there are a few ruins on the island from the Second World War. In fact the concrete posts which run the length of the causeway were put there to protect the River Forth from enemy boat attack during the war. Other than the remains of the war defenses there is not much on the island. However the constant feeling that the tidal clock is ticking and the views of the the Forth and in particular the Forth Rail and Road Bridges makes the game of tidal roulette worth while.
To celebrate passing the tidal challenge stop for a beer at Cramond Inn which is a few metres up the hill from the start of the causeway to the island. It has a good range of beers and a excellent menu. Buses from the city centre stop not far from the Inn (Lothian buses Number 41 from Queensferry Road 30 minutes )