Rocky mesas, canyons and arroyos break up the monotony of kilometers of shifting dunes.

岩石台地、峡谷和旱谷点缀在绵延几千公里的流动沙丘中。

He liked to position structures over waterfalls, on steep slopes, at the bottom of arroyos.

他喜欢将建筑物置于瀑布上方，或者陟峭的斜坡处，或者是沙漠底部。