Abatis

 

An abatis, abattis, or abbattis is a field fortification consisting of an obstacle formed of the branches of trees laid in a row, with the sharpened tops directed outwards, towards the enemy. The trees are usually interlaced or tied with wire  

I came across this while reading Vicksburg by Donald Miller.  I can't help but thinking about this as an emotional think we do, too.  We create these intertwined defenses to keep from being vulnerable -- to others or ourselves.