Combine two of londons great attractions with this flexible tour of the river thames and entrance to london dungeon hop on and hop off your river sightseeing cruise from four conveniently located piers for 24hr and delve into one of londons goriest and atmospheric attractions the london dungeon takes you on a journey into londons murky history travel the narrow streets stalked by infamous jack the ripper meet murderous king henry viii or if you dare get up close and personal with punge