Little known is that those in the Southern Rail region travelling in a 3 or 4 can go anywhere, anytime weekends or after 10am Monday to Friday for for a total of £20!! AND visit as many of the stations as you wish!
1 or 2 adults traveling can do so for £10 each
AND children can travel £1 when accompanying adults.
The only restriction is if visiting London cannot leave there weekdays between 4pm and 7.15pm
THE TICKETS ARE CALLED DAYSAVE
Do not be put off if your local station does not sell these tickets - buy at Tourist Information Centres or online at southernrailway.com (with slight booking period restrictions)