Kevin Sites provides some insight in his latest dispatch about the tunnel system built by the Vietnamese:

They are a marvel of engineering, weaving underground for several stories and linking together living, dining and meeting areas, as well as weapons factories and subterranean hospitals, complete with operating rooms.

But perhaps their most significant function was to allow the VC to coordinate their operations in the south, both by utilizing surprise attacks then disappearing underground, while also inserting agents and saboteurs into the south.

Because of their strategic value, the entrances to the tunnels were well-protected both by camouflage and booby traps.

Yes, the strategic value was a factor but perhaps not as much as the low cost of reducing inhabitant vulnerability with simple countermeasures, which also probably diminished threats as well (few would want to enter an unfamiliar tunnel of traps). Not sure why Kevin ends with these quotes, other than to warn anyone considering a visit to the tunnels to expect a harsh and realistic rather than romantic story:

“We expected it to be about the ingenious ways used to escape detection,” says Nicky Ashby, 26, from London. “But instead, it’s more about techniques of torture with all the booby traps.”

“It seems to me like it’s celebrating the violence rather than the idea of their perseverance,” says another, who doesn’t want to be identified.

Nice story about an archaeology buff who is building a castle from scratch in 13th century style. Along with period building material and methods, they are also considering how to defend from period attackers:

Our guide blended humor with the history lesson and had us play the role of invaders to explain how even the smallest architectural details helped protect castles.

Some examples: A staircase turns clockwise, forcing invaders to transfer their spears to the left hand and giving the defense an advantage. An extra-tall step requires them to take off their chain-link armor to scale it. Anyone who actually makes it up the stairs alive would have to bend over to pass through a low doorway — giving the castle’s hatchet-armed defenders a prime crack at their necks.

Sounds like fun, but the real question is what will they do to defend against other period threats like The Black Death. Will these history buffs bathe regularly and keep their lodging clean or find scapegoats to torture and burn?