Northern Region is noted for its traditional African scenery. The land is mainly savannah and the population, mostly Muslim, is sparse on the plains. Tamale, with a population of about 300,000, is a mixture of cultures and religions. On Damba festive days, the king and rich chiefs ride on decorated horses. The major rivers are Black Volta and White Volta that flow into lake Volta. Salaga was a slave-trading centre. The region's markets are full of cotton and local fabrics. Yendi is the royal town of the Dagomba people. In Mole national park there is a motel, swimming pool, bar and restaurant. Larabanga mosque is Ghana's oldest mosque built in 1421 and nearby is Larabanga mystery stone that neither man nor machine can move.