Egyptian tomb security evolved as an arms race against robbers. Early dynastic tombs used harder stone for portcullises; mastabas grew to have six slabs weighing up to 42,000 lb. The Bent Pyramid introduced an oblique sliding design. Corridors stayed narrow (~1 sq meter) to limit levering attacks.
Key facts claimed:
- Early dynastic tombs used portcullises made of harder stone than surrounding bedrock as security barrier
- Mastabas had increasingly large portcullises weighing up to 42,000 lb, sometimes with up to six slabs
- The Bent Pyramid of Snefru was the earliest pyramid to contain a portcullis
- The Bent Pyramid's portcullis slides at an oblique angle, penetrating below floor level to neutralize levering attacks
- Egyptologist Reg Clark was first to comprehensively examine tomb security evolution

