Nuts to Crack

Following are 10 old Icelandic Riddles. The answers are at the bottom of the page, but no peeking, until you have tried to answer them.

1.
What wall, high and wide, is yellow, red, green and blue?

2.
What grows with the roots upwards and the crown down?

3.
Who is not my brother, not my sister, yet is the child of my mother?

4.
Who runs over the ocean, and never wets his feet?

5.
What is the strangest prison God has used to house a prisoner?

6.
A male went out one night and did what God can not do?

7.
I am both the eldest and the youngest in the world?

8.
I write twelve, take two off, and four remain?

9.
A full house of food, but no door to be seen?

10.
What is the easiest thing in the world?