Bronze Age tombs in southern Arabia were constructed above ground in a dry wall manner and on occasion contained decorated statue-menhirs (see above) or attached "tails". However, other tombs were constructed entirely different. So-called box tombs were built underground with side compartments constructed of small slabs containing rubble fill. Could this distinctive style have reflected either "troughs" associated with numerous nomadic Bronze Age sites or permanent house foundations also found throughout southern Arabia? The central box contained the burial chamber. This chamber was often lined with flag stones. Excavated examples are known from the Shihr vicinity. In the Wadi Masila, such tombs contained small amounts of copper/bronze, as well as numerous stone and marine beads, many highly worked.