For those who do not know, this concept originated on the railways in Britain long ago as a "mystery excursion", in this case a whole special train was provided. They were popular in holiday times from industrial towns at weekends, and from seaside resorts during the week, especially if it was suffering a spell of "British Summer" weather. Passengers attempted to guess route and destination (often hysterically badly) as the train progressed. About half an hour before arrival, the guard came through and told everyone where they were going.
There was a fund of stories associated with them, as you can imagine, such as those from a holiday resort discovering they were being conveyed back to their own home town; while everyone else went round the tourist sights they could go home for a cup of tea.