Ja, they look a lot like old-fashioned Lincoln Logs, but they are made by Maxim, not by K'nex (it's true - K'nex now owns the Lincoln Logs product line).
These are Tumble Tree Timbers, and I am kind of fond of them. This structure is one of four that can be built at the same time with the 300 piece set, which has reasonably decent plans for three of them, including this one. So I have no excuse for forgetting the chimney.
Admittedly, they don't have the quality of Lincoln Logs, old or new, but the quality isn't bad, as are some of the other makers. The part mix in my sets are very good - simple, versatile, and all-wood.
Though I admit to having had to add a little metal, in the form of a penny or two to keep two flat roof boards from falling into notches. Those are Lincoln pennies, by the way, and if you zoom in (most all my blog images can be expanded by clicking), you'll see Abe sitting on a log.
I find a certain charm in building with linking logs in their natural form, and you have to give credit to the Lincoln Logs folks for providing a few sets that are all wood. If somebody would like to send me a set, I'd be happy to review them. For the time being, I am happy with the mix of old & new Lincoln Log sets and similar items I have, without buying more.
I even have fun with the modern Lincoln Log sets with plastic pieces, such as the Frontier Farm below. I especially like the cow.
Modern Lincoln Logs have a flat top & bottom, which can help beginners, and are very nicely designed & made, if you accept the plastic components. And much of the time, I do. I have several of the little totes, each of which has well-done instructions for one building and pictures of variations. You can mix the sets up for more interest, of course. Fortunately, I am pretty firm about sorting the pieces back in the original totes, so I can play when I need something easy.
Square or round, linking logs is Good Block Play.
This is my 200th Block Play post since starting on June 5, 2005. There are a few posts dated before that start up date, but they are mostly older photographs to which I gave the date of the photograph. The intention throughout has been to post my Block Play of that day, or sometimes the previous day, and perhaps ramble on a bit. There are also a few more posts partially written or almost finished but needing pictures. Maybe the reason they sit unfinished is because they don't follow that theme.
Between now and Christmas my intent is to emphasize things that are currently available, to help folks trying to chose gifts - I get a lot of queries & feedback on that. After the new year I hope to explore older items more.
Disclosure: I get a commission on Block Play Store sales in the form of an Amazon gift certificate, delayed two months, whenever the commission balance exceeds $10. I got one in September, but won't see another until next year. The average recently has been about $3 per month, with $1 in October. Obviously, I do it for fun, not for the big bucks. Amazon tells me what folks buy, but not who. It might be more fun if I "knew" my customers, but Amazon is WAY better at customer service than I am.
There are other sources listed in the "Links" sidebar, and occasionally in posts. Please mention this blog if you order from them. They don't pay me anything, but sometimes I get an extra booklet or a sample to try out.