In what specific ways does Herot contrast with Grendel's home?
Herot (the "heart" of the people) is the center of activity of the town. The throne where the King sits in Herot is protected by God. It is bright, covered in gold and other precious metals and gemstones. It glitters and is a happy, social place.
The lair where Grendel lives is anything but bright. It is dark, gloomy, and unpleasant. It smells, and the water above it bubbles with foul smelling gas. No one goes there but Grendel and his mother, so there is no social atmosphere. It is a den of evil as they are descended from Cain, who murdered his only brother, Abel. They are unkind, unpleasant, and just plain grumpy. God does not protect them, nothing good comes from this place.
The mead hall is a place of comfort for the warriors. It is a place where loyalty is rewarded by the king and reputations are gained. The author describes it as a place of light, warmth, and good cheer, where the community meets to eat, drink, sing and enjoy one another. Contrasting this is the description of Grendel's home. Here is a dark, murky place where the water itself burns and the animals fear to go. The author goes so far as to say animals would rather die than drink from the lake. There is no community, only the lonely, outcast souls of Grendel and his mother. It is a place of doom and isolation.
Herot is a "mead hall" or a place where men gather to drink and socialize with friends. It was originally built for soldiers to come before and after battle to relax and have a good time. Herot and Grendel's lair are almost exact opposites. Grendal lives alone, away from all human and probably all animal society. According to the text, Grendel attacks Herot because he cannot stand the joy and the light. By inference, we can conclude that Grendel's lair was a sad, dark place.