It seems fairly obvious that at some point two of Google’s most popular products, Google Maps and Google Earth will become one in the same – and that conjoinment moved one step closer today as Google Maps added a ‘Terrain’ button.

As you’d expect you can now see the contours of the land over the entire United States – but it’s not just for the United States, the feature has already rolled out for the entire world. Check out the Himalayas, the Alps, it’s all there. To show off this new great looking new layer, here’s a map of the highest places in the U.S.

To make room for this new button, the ‘Hybrid’ button has been axed, but that feature is still available directly below the ‘Satellite’ button when you click that.

The next step for Google Maps will probably be 3D views – not ‘Street View’ (which should soon hit Europe and Australia by the way), but rather false 3D models representing buildings just as Microsoft is doing with Live Maps in select cities.