The relative adverbs can be replaced by relative pronouns or by prepositional phrases with relative pronouns as complements.' (Sidney Greenbaum, Oxford English Grammar.

O'Rourke, 'Whitewater.' Age and Guile, Beat Youth, Innocence, and a Bad Haircut.

'On my first night in town I went to a restaurant called Cock-of-the-Walk, where they had deep-fat-fried catfish and deep-fat-fried every other thing you can think of on earth including-seriously-deep-fat-fried pickles.'When I am run down and flocked around by the world, I go down to Farte Cove off the Yazoo River and take my beer to the end of the pier where the old liars are still snapping and wheezing at one another.' (Barry Hannah, 'Water Liars.' Airships.'The reason why so many wealthy Americans come to Europe is to avoid this obligation to work.' (Alexis de Tocqueville, Democracy in America, 1840).This Hollywood restaurant is one of the quintessential power spots, especially on Mondays, when stars abound and tourists are discouraged.'It must be wonderful to live in a safe and timeless place, where you know everyone and everyone knows you, and you can all count on each other.' (Bill Bryson, The Lost Continent.

What is a relative adverb