Lakes:

Colonies built on Lakes that are at least 10 (?) squares large can build shipyards and construct the smaller ships to operate on the lake (Sloops, Gunboats (?)).

Mountain Crests:

These are squares that are impassable to all units unless they contain a Pass.

Rivers:

These will be of Major and Minor types. Both types will aid in production and can mitigate Droughts, but leave the square open to Floods. Both Major and Minor Rivers are a obstruction to Wheeled units (Wagons, Artillery, Treasure Trains). Such units expend their full movement allowance to cross except at Fords. Major Rivers are an Obstacle to all Wheeled and Mounted units. They must expend their full movement allowance to cross except at Ferries. (Units still receive a bonus for moving along the river. The penalty only applies to units trying to cross.)

Waterfalls:

Increases Manufacturing of all types in Colonies built on such a square.

Gold:

Can be mined as a resource, but only in small quantities. (Gold Pieces, not tons.)