Glen Roy is an area in Scotland where we can see something very interesting. A very long time ago, there was a big ice sheet covering the land. This ice sheet was so big that it was many times taller than the highest mountain you can see today! Can you imagine how big that is?
When the ice started to melt and get smaller, it left behind some interesting things. The ice had caused big rocks to move around and scrape away the ground, leaving big scratches on the rocks.
In Glen Roy, we can see something even more special! The ice sheet had made some hills that were like big stairs. These hills are called "parallel roads" because they look like roads that go along the hillside, but they are not made by people or cars. They are made by the ice!
When the ice melted and made a big lake, we can see the "parallel roads" where the water used to be. It is like a very big bath tub!
Scientists who study rocks and land can look at the "parallel roads" and tell how high the water used to be. They can even tell which parts of the hills were covered with water for longer than others.
It is very exciting that we can learn so much about our Earth by looking at things like the Glen Roy "parallel roads"!