Having been crammed onto a small island for the last few millennia, the Japanese have become masters at creating the illusion of additional space in small gardens. The Japanese have developed several techniques that use perspective to add perceived distance to actual distance.
One of those techniques is called altered perspective. The brain perceives small objects as farther away in relation to larger ones. By simply placing larger objects close to the viewer and smaller landscape elements beyond, you exaggerate the illusion of perspective. As a result, the perceived distance between the objects becomes larger (as does your yard). The Japanese also employ bonsai -- miniaturized plants -- to alter perspective as well [source: Young, et al].
Miegakure is another Japanese technique that extends the size of a yard beyond its actual borders. By adroitly cluttering the landscape so that elements are hidden by other elements, the landscape isn't revealed all at once [source: Young, et al]. A garden unfolds as the viewer ventures into it, obscuring its actual size.