A literary symbol is something, often an object, that stands for a significant concept or series of ideas. Often a symbol is emblematic of the values of the characters. In Beowulf, some of the most important symbols are Hrothgar's mead-hall, Grendel's cave, Grendel's arm and head, and the dragon's treasure-trove.
Hrothgar's great mead-hall, Heorot ("Hall of the Hart"), functions as both setting and symbol in the epic. It is much more than a place to drink. Symbolically, Heorot represents the achievements of the Scyldings, specifically Hrothgar, and their level of civilization. The hall is a home for the warriors who sleep there and functions as a seat of government. It is a place of light, warmth, and joy, contrasting with Grendel's morbid swamp as well as the dark and cold of winters in Scandinavia. In Heorot, Hrothgar celebrates his victories and rewards his thanes (warriors) with various treasures. The building is like a palace. It towers high and is compared to a cliff. The gables are shaped like horns of the hart. People from neighboring tribes have respectfully contributed to the rich decorations and intricate designs. The hall is also symbolic in that it is the setting of Beowulf's first great battle, the defeat of Grendel. When Grendel invades the hall, he knows that he strikes at the very heart of the Scyldings. That lends special meaning to his victories and to Beowulf's eventual liberation of the hall from the ravages of the ogres.
