I have a trip planned for myself and my wife on a Monday in mid August. We are staying at the PI in Welwyn and intend catching one of the earliest off peak trains into London, stay the day seeing the sights, travelling around on the tube and returning in the evening, probably around 8-9pm.
I see there are trains available for £13.50. Is it worth buying these on line in advance or just to get them at the station on the day. Is there a decent ticket office at the station?
Also, I see there is a McDonalds near the station, is it open yet?