Canterbury in 3 days: Canterbury Cathedral (UNESCO: Thomas Becket murdered December 29 1170 by four knights of Henry II — the pilgrimage site that inspired Chaucer's Canterbury Tales (c. 1387–1400)), St. Augustine's Abbey (founded 598 CE — the oldest Christian monastery in England), St. Martin's Church (the oldest parish church in continuous use in England: built partly from Roman tiles), the Beaney Museum (free: the Rupert Bear originals, the Roman mosaics), the Canterbury Tales museum, a day trip to Whitstable (the oysters praised by Pliny the Elder in 77 CE) and the Reculver Roman towers on the Thames Estuary.