Marco Werman talks to writer Robert Macfarlane about walking "The Broomway" - a path off the southeast coast of England that's only navigable when the tide is out.
For today's Geo Quiz, we're looking for an ancient path off the east coast of England.
The path starts at Great Wakering, on the coast of Essex, and it ends at Foulness — an island separated from the mainland by narrow creeks.
Here's the interesting part: when the tide is in, this path is under water.
You can only walk it when the tide is out.
But if you time it right, it's unforgettable.
The answer is The Broomway.
British writer Robert Macfarlane walked The Broomway, and he writes about the experience in the current issue of Granta magazine.
Macfarlane says it was "the eeriest, the unearthliest and the most memorable walk" he's ever taken.
Macfarlane's Granta article is excerpted from his forthcoming book, The Old Ways.