This county in the West Midlands is famous for the homonymous sauce. Foreigners often have problems to pronounce the name, which, despite being written "Worcester" is spoken "WUUST-er". The highest point in the county is the Worcestershire Beacon (425 m asl). The Malvern Hills in the south of the county and Herefordshire are made up mainly of 1.2 Ga old volcanic igneous rocks and metamorphic rocks. The rest are undulating hills and farmland crossed by the Severn valley. The Severn is the United Kingdom’s longest river. The geology is not suitable for karstification, the only underground sites are subterranea which are also quite rare in the rural county. The most spectacular underground sites are two large bunkers which are mentioned on Subterranea Brittanica and otherwise, but unfortunately are not open to the public.