This world has many big trees on it look at the map to see.
Download and Installing steps below:

1. download it

2. move the file from downloads to your desktop.

3. open minecraft

4. click edit profile

5. click open game dir

6. click on the file name saves

7. drag the file you downloaded into saves

8. close all programs

9. start minecraft and

10. Go to singleplayer

11. click on the world Big Trees

12. click play