Find 3 quotes that describe the topography of the Song Tra Bong.

As Rat described it, the compound was situated at the top of a flat-crested hill along the northern outskirts of Tra Bong. At one end was a small dirt helipad; at the other end, in a rough semicircle, the mess hall and medical hootches overlooked a river called the Song Tra Bong.

All morning Mary Anne chatted away about how quaint the place was, how she loved the thatched roofs and naked children, the wonderful simplicity of village life.

To the north and west. the country rose up in thick walls of wilderness, triple-canopied jungle, mountains unfolding into higher mountains, ravines and gorges and fast-moving rivers and waterfalls and exotic butterflies and steep cliffs and smoky little hamlets and great valleys of bamboo and elephant grass.