You are heading towards Berkeley on Interstate 80/580.   Passing Emeryville, get in right hand lane, then:

1. After Emeryville, exit RIGHT at the Ashby Avenue/Shellmound Street offramp.
2. The exit ramp splits – take RIGHT hand option, marked ‘Shellmound’.
3. Turn LEFT where ramp ends, onto Shellmound Street.
4. Continue straight to the end, where there is a parking area and a big steel gate keeping the public from turning LEFT onto the causeway that separates the pond on the south from the estuary on the north.   Go through that gate (close it after you), across causeway, then RIGHT for 100m.