... on Sunday Well there's the guided Brunel tunnel tour, leaving from just outside Rotherhithe Station - I presume the local are used to having their local station swamped by now! http://www.londonopenhouse.org/london/search/detail.asp?ftloh_id=1798 A thoroughly interesting visit if you ask me, lead by enthusiastic and knowledgeable "tour guides" (I'm sure it doesn't do them justice)....