Mika and Mochi's first play tower (as seen here) was getting rather unstable and wobbly lately, so we'd been thinking about finding an alternative. Mochi loves to run straight up trees when we go outside, and we really wanted to get something that would let her do that inside the house unencumbered by landing shelves.
This is what we came up with:
Essentially we picked up some plywood, a 4x4 post, and a few brackets and screws. The top shelf and sisal rope was salvaged from their old tower. Here's a simple explanatory drawing for those who are interested:
With how heavy the 4x4 is, I wouldn't trust this thing to stand on it's own, but with the wall supporting it (it's screwed into studs), it's perfectly stable. We would have liked to use something lighter and rounder like a cardboard cement form, but this was the right size, inexpensive, and gets the job done. It is a bit difficult to get the sisal tight on it - my hands were hurting the next day or two afterward.
Mika took to it instantly. She's always the braver of the two. In fact, we had to lock the girls out of the living room while we assembled it because she kept flinging herself at it wanting to climb it. Please pardon the poor lighting in these pictures. It's a weirdly lit corner of our house.
Mochi came around fairly quickly with a bit of encouragement.
Now they practically fight for who gets to sit on top and they love running up and down when chasing each other. Their favorite dismount is an upside down tension method where they walk face downward with their paws on the tower and their backs pressed firmly against the wall. Sometimes Mochi climbs partway up just so she can stand upside down awhile.
Leaping from the top shelf onto the back of the couch is another popular dismount method.
Eventually we intend to add shelves to the walls so they have multiple places to sit without hindering their climbing space, but we haven't quite gotten to that yet.
The piles of pillows in the shots below are because Mochi is a klutz and we were vaguely concerned about her getting hurt if she fell while figuring out climbing/dismounting methods. We weren't wrong about her taking a few tumbles, so I'm glad I put them there.
They've gotten pretty pro at it now though.