Fortifications of London

The defensive wall of Roman Londinium, first built c. AD 200, stretching approximately 2.5 miles and enclosing 134 hectares. Constructed with a rubble core bound in hard mortar and faced with squared Kentish ragstone blocks (35,000 cubic metres quarried near Maidstone), with distinctive red tile bonding courses every fifth or sixth row. The wall stood over 6m high and 2.5m thick at the base, incorporating an earlier Roman fort at Cripplegate (c. AD 110-120). Extensively rebuilt in the medieval period, reaching over 10m with additional gates. The Tower Hill section, at 10.7m, is the most substantial surviving portion, revealing both Roman and medieval construction layers.