Better Dino Pen 1

Just an idea for the dinosaur mod for MineCraft

The sunken pin is 33 blocks by 40-something blocks wide, and 20-ish blocks deep. the perimeter of the bottom is a 2 block wide, 10 block deep trench of water. An obsidian wall (or obsidian strength material) should make up at least as tall as the dino should make up pen's wall to prevent escape of dinos capable of breaking blocks.