Added Comment: As Ed said in his comment to this post, these products are available from Acheson Creations. Looks like he has a large number of very interesting terrain pieces and various forts and buildings.
The first piece is a 2.5" segment of four wicker gabions.
They are pictured with an Old Glory Eastern Woodland Indian.
The second type is a 3" timbered wall that is constructed with log walls and packed with earth.
A Foundry British light infantryman is firing from behind it.
There are also two types of 2.5" stone walls, one with several upright wooden posts at one end.
Here shown with a Conquest Colonial Ranger firing at the enemy.
And the other is just a slightly tumbled down stone wall.
Shown here with a Redoubt Colonial Ranger.
I've already used the wicker gabions in my Assault of Fort Khalaam Victorian colonial game last summer and the gabions and the timbered walls in the 18th Century Action at Eisenmuhlen game from this past fall.
These pieces are cast with some sort of pearl gray plastic or resin that feels very slick. Even after washing them in warm, soapy water, I had to spray them with Krylon Fusion paint for plastic before my brush-on primer would stick to the entire surface. But that was just a small bump in the road to getting them painted and not a reason to avoid them.