Angostura is a brand of cocktail bitters invented in 1824 by Dr. Johann Siegert. Born in Germany, he traveled to Venezuela and was appointed by Simon Bolivar to run a militrary hospital in the town of Angostura. Originally intended as medicine, Dr. Siegert's Amargo Aromatico (as it was originally called) was renamed after the town in which it was made.
Political unrest caused the sons of Dr. Siegert to move production to Trinidad, where it has been ever since. Angostura bitters have no Angostura bark in them — the bark, like the bitters were named after the town itself. While the recipe is a secret known by only five people, it smells and tastes strongly of baking spices, lime and orange oils. It's nearly 90 proof.
Angostura is an indispensable ingredient in cocktails, especially Tiki drinks. Some people even use it in the kitchen to flavor sauces or meat.
They also make an orange version flavored with both sweet and bitter oranges. It has a pure orange flavor. It is more difficult to find that regular Angostura bitters. Angostura orange was introduced in 2007. Angostura orange is 56 proof, where regular Angostura is nearly 90.