Landscapes from Coherent Noise
You can try it out here:
https://bergin.github.io/Landscape-Generator/
Slide the 'constrast' slider to build the mountains and lakes; 'rotate' alters the landscape (rotates the Perlin noise vectors)
Keys:
Arrows for forward, back, left and right.
1 & 3 to Yaw left and right
w & x to Pitch forward and back
q & z to Lift up and down
a & d to Roll left and right
Hope you like it!