My favorite place in Angola is the El Arco Oasis south of Namibe on the coastal highway. Drive south on the highway until you see a small metal sign that says "Bem Vindo ao Arco" on the lefthand side. Nearby is another small sign - an arrow pointing into the desert. With no road, only tracks in the sand, drive in the direction the arrow points and wind through some dunes until you come to a tiny town. Park under the large tree, then hike a short distance to see amazing rock formations and a huge oasis in the middle of the desert - truly spectacular in scale and beauty.
Afterwards head into Namibe for delicious fresh crab and lobster at casual plastic-table restaurants by the bay.