The Ridge tile is inaccessible by ground units. There are up to 5 indestructible Mountains on the tile.
Unlike the Water tile, the Ridge tile does not help nearby City, Town, Farm and Outpost tiles grow.
Ridges differ from mountains in that they add no extra humidity to adjacent tiles.
As each ridge counts as a separate (indestructible) body when calculating damage, ridges provide excellent protection to zeppelins. A full ridge with 5 peaks reduces the chance to hit a zeppelin on that tile with a bombard or shell to 1/6.