I wander towards the Sea-Obelisk in the mouth of Yantlet Creek, which could harbour 50 ships in a storm before it silted up.
It marks the limit of the ownership of the Thames by the City of London. Paired with the Crow Stone, the two stones mark the Yantlet Line, running north-south across the Estuary.
Both are 34 miles from London Bridge. The Medway stone carries the inscription “God Preserve the City of London”.