recently i went to a village church in Herts/Essex area and while strolling round the back of the church i saw an odd little door with a grill on it, i had a peak and inside and you just make out a pile of lead lined coffins piled up. it was an entry to the church's vault. i always assumed such things were cemeted up and inaccessable.
the other one is a church up near Kings Lynn, hidden behind a wooden door they have a 300 year old waxwork of a local lady, both of these things are proper nightmare material.