Not sure if this is what you are looking for... there are some half-logs here:
http://www.undergroundreptiles.com/hideboxes.htm
They're not real, but here is the description:
The Turtle Hut is the best choice in natural-looking hides. This hide looks like wood, but is made of resin instead, making it safe for full or partial submersion. Perfect for turtles, tortoise, or other reptiles.
Small - 3.25" x 3.5" x 1.75"
Medium - 4.75" x 4.75" x 2"
Large - 6.75" x 5.5" x 2.75"
XLarge - 8.75" x 7.5" x 4.25"
Giant - 10.75" x 10.5" x 5.5"