How could any BSF old-timer forget this?!
A tip now for those going to the GP (possibly too late now), when the GP finishes get the tram in the wrong direction (so carry on to Bila Hora), its only about 2 stop further along and it turns around and comes back, takes all of 4 or 5 minutes. There no queue so you get on quickly and you get a seat. The alternative is to stand in a queue for 30-40 minutes to stand on the tram back to the centre of Prague.