It’s not every day that you can eat in the oldest restaurant in the world (the Guinness Book of World Records has recognised it as the oldest – established in 1725) that has also appeared in many novels about Madrid, most notably Hemingway’s The Sun Also Rises , and Frederick Forsyth's Icon and The Cobra . The secret of its staying power is fine cochinillo (roast suckling pig; €23.95) and cordero asado (roast lamb; €23.95) cooked in wood-fired ovens; the angulas (baby eels) at €101 a dish is probably beyond the reach of most. Eating in the vaulted cellar is a treat. Yes, it’s filled with tourists. And yes, staff are keen to keep things ticking over and there’s little chance to linger. But the novelty value is high and the food excellent. Contact Insider's Madrid for guided tours (The Botín Experience) of the restaurant.