Gwyn-Haro is an ancient fortress located within the Modran Hills of Gwynne.

In the early Third Age, the castle was built by a Modrani warlord named Gareth Gwynnett. Over the years, the castle was destroyed and rebuilt several times.

Today, it is home to House Carcano, a Thannish noble family fiercely loyal to the Crimson Throne.

The name for the Kingdom of Gwynne is derived from this castle.