Rock is a confectionery made and sold in many of the UK's seaside holiday resorts. As the character Ida says in Graham Greene's novel Brighton Rock[?], "It's like those sticks of rock: bite it all the way down, you'll still read Brighton."
... such as Tijuana, Mexico, where promises of effective treatment for diseases such as cancer are made. (Usually over the internet.)
At these institutions, untrained, or ...