Lots of children are looking forward to playing outside in the summer, but they need to keep away from dangerous train lines, a rail company has warned.
The focus of the campaign is live rail tracks, where people can be electrocuted if they touch them.
Nearly 50 people have died in the past year from live tracks, and around one in four of these were teenagers.
A spokeswoman for Network Rail said most people don't realise how deadly the live tracks are.
The rails are so dangerous because they have electricity passing through them.
So young people are being warned not to play near railway lines to stop more accidents from happening.