GROWING up has lots of milestones and one of which, according to research, is being tall enough to go on the best rollercoasters.

To celebrate its reopening on March 20, Thorpe Park is having a Happy Height Day.

Research has shown that the average age a child reaches the magical height of 1.4m, where they can ride the biggest rollercoasters at the theme park, is 10.

The first 500 children through the doors between 1.4m and 1.5m on Saturday, March 22, and Sunday, March 23, will get free entry for them and a guest.

Terms and conditions apply, go to thorpepark.com