You're not a true chocolate cake aficionado if you haven't sampled Sacher Torte. And the only place to order a slice of the world's most famous (and decadent) chocolate cake, with its signature apricot layer, is here in Vienna at the Hotel Sacher, where it was first served in 1876, 50 years after the son of the hotel's original owner - Eduard Sacher - created it. While professional and amateur chefs around the world have attempted to recreate the cake's prized formula, the original recipe remains a closely guarded secret, so it's worth dropping in for coffee and cake even if you can't stay overnight - for this authentic (albeit calorific) treat. A favourite retreat amongst aristocracy, politicians and artists this five-star Leading Hotels of the World member offers 152 rooms and suites, exquisite Viennese dining and a Spa offering a very different chocolate experience.