Oregon, Maryland was the site of an iron furnace that operated from 1844 – 1857. Some ruins of the original buildings are visible in addition to the remnant of the iron furnace, scattered mining pits, and a marble quarry. 
Although the park is very popular and surrounded by suburban and industrial sprawl, the area retains a natural feeling and the ruins are un-commercialized. The ruins are in an area that’s moderately developed for a kids’ outdoor education center. So scattered around the historic site are such things as interpretive signs, an indoor nature center, a sandbox, and, strangely, brightly painted trees.
The nearby nature center is worth visiting even if just to see the archaeological display. Modern scientific excavations reveal the extent of the town site and insight into the lifestyles of the early European inhabitants.
Some structures at the town site are not what they seem. This well house and tenant house are modern reproductions, historically accurate but not original.
On the east side of the park, where outdoor concerts and held now, was previously a ski slope. These features on the top of the ridge are likely remnants of the old ski lifts.
For more information on visiting the ruins of Oregon, Maryland and the Oregon Ridge Park, here is the official website: https://www.oregonridgenaturecenter.org/