Building a permanent bridge over the defensive moat of a 17th century fortress might send the wrong message to an invading army. So modern-day Dutch engineers have come up with a clever way of disguising the pathway - by building it under the moat's waterline.
The West Brabant Water Line is a series of defensive fortresses, cities and waterways in Halsteren, the Netherlands.
After falling into disrepair it had been recently restored, but designers thought it would be inappropriate to go against the original design and build bridges over the moats.
Instead, they came up with an "invisible" bridge that sits within the moat and would allow people to cross virtually undetected from water level.
The award-winning Moses Bridge - so named as it invokes the biblical image of Moses parting the Red Sea - is now a landmark feature of Fort de Roovere.
Ad Kil, a spokesman for architects RO&AD, said: "The fort now has a new, recreational function and lies on several routes for cycling and hiking."
"Of course, it is highly improper to build bridges across defensive moats, especially on the side of the fortress the enemy was expected to appear on."
"That's why we designed an invisible bridge. Its construction is entirely made of wood, waterproofed with foil."
"The bridge lies like a trench in the fortress of the moat, which is shaped to blend in with the outlines of the landscape."
"The bridge can't be seen from a distance because the ground and the water come all the way up to its edge."
He added: "When you get closer, the fortress opens up to you through a narrow trench. You can then walk up to its gates like Moses on the water."