S1, E5: Julia follows in the footsteps of Sherlock Holmes in a classic English walk on the South Downs, taking in the white cliffs of Seven Sisters, Beachy Head and the seaside charm of Birling Gap, where the sea is eroding the cliffs at an alarming rate. Her walk ends at the Belle Tout lighthouse which had to be moved away from the cliff edge at the cost of a quarter-of-a-million pounds.