This pass is very susceptible of defence by a smaller against a larger force.
Again, the highest point of the road-bed between Vera Cruz and the City of Mexico is over Rio Frio mountain, which also might have been successfully defended by an inferior against a superior force.

But by moving north of the mountains, and about thirty miles north of Puebla, both of these passes would have been avoided.

The road from Perote to the City of Mexico, by this latter route, is as level as the prairies in our West.

Arriving due north from Puebla, troops could have been detached to take possession of that place, and then proceeding west with the rest of the army no mountain would have been encountered before reaching the City of Mexico.

It is true this road would have brought troops in by Guadalupe--a town, church and detached spur of mountain about two miles north of the capital, all bearing the same general name -- and at this point Lake Texcoco comes near to the mountain, which was fortified both at the base and on the sides: but troops could have passed north of the mountain and come in only a few miles to the north-west, and so flanked the position, as they actually did on the south.
It has always seemed to me that this northern route to the City of Mexico, would have been the better one to have taken.