One of the hidden gems of the Harn fan world is Lythia.com with hundreds of downloads for Harn. All of them free and many of them as good quality as the official releases.
Even among many excellent Lythia download there are a few that stand out. Among them the Harn Pottage series. Each of are well a pottage of a variety of adventure and locales usable for a Harn campaign. But because Harn shares with other fantasy RPGs, like DnD, a medieval background, Harn Pottage are usable with just about any fantasy RPG including the latest DnD 5e.
ANd because they are designed to be generic they are about the easiest to adapt of the various Harn material out there.
The latest is Harn Pottage IV, in it are a village, an adventure associated with the village, a pirate cove, a scout post, a walled town, and a elven vineyard. All of them well written and suitable to be placed in many fantasy settings. The release of a entire walled town of 4,000 people I found particularly impressive.