>>4376845 (lb)
A Bolt hole is a safe house for The Evil Empire (or any escape/bunker type place of refuge). The theory we are going on is that these cabal dicks are so immoral they would use graves as shields.
Arlington , VA is a huge cemetery. I assume Alexandria , VA is a cesspool of scum and villainy , so I started to dig (ha) around there. I can confirm Christ Church in the city was renovated in 1985/86.