Madeira is one of the most extraordinary wines in the world, and one of the least understood. Produced on a small Portuguese island in the middle of the Atlantic Ocean, it is a fortified wine that has been deliberately heated as part of its production — a process that sounds counterintuitive but results in a wine of remarkable complexity, striking acidity, and almost mythical longevity. A well-made Madeira does not just age well. It is, for practical purposes, indestructible.