So close to the centre of London, yet I suspect most Londoners have never heard of the Maplin Sands. Until quite recently it was owned by the Ministry of Defence and is still administered by a company on behalf of the ministry. I drove my van through check points to get here - all were open and unmanned.
As can be seen in this film, the Maplin Sands are mudflats on the northern bank of the Thames estuary, off Foulness Island, near Shoeburyness, Essex.
Road access is via Shoeburyness, once having reached this spot, parking is not a problem, probably because next to no-one ever goes here. I do not know what the situation is on staying overnight, there are no signs forbidding it, but lets not forget it is a live firing area!
In 1973 plans were approved for a third airport for London, the Thames Estuary Airport. The project included a deep-water harbour suitable for the container ships, a high-speed rail link to London and a new town for the accommodation of the thousands of workers who would be required. These plans were abandoned in 1974.