What's some cool diy projects for toddler outdoor play?

OSB is virtually waterproof, and you can get plans for a playhouse without nails or screws. I reckon you can make a sandpit and a playhouse with $250. you can get used or shopsoiled OSB cheap.

Make that playhouse.

But inspect it periodically . .it's not going to rot overnight, and no matter WHAT you have for your kid to play with, you DO need to keep an eye on how intact it remains.

Sandboxes are also good ... either wood-framed or plastic ones that you fill up with sand.

So your house made of wood is rotting and the nails used to build it are dangerous? Really??

use dry wall screws to put stuff together == avoid the use of nails == countersink and putty over then paint

Sandbox. Kids love those. I made a huge one for my kids that had a jungle gym in the center. They played there all the time.

Wood will rot over time, yes, but so what? The kids grow up.

I built a shed in my back yard from 4x4s and wood fence panels. The roof, however, was flat and the 4x4s were tall, so I could add railings between those uprights. This became a ready-made play structure that was also a handy storage shed. Some of the roof lumber ran long which became a shelter over rabbit hutches, but it could just as easily have been made into overhead beams for holding up swings.

Four fence panels @ $30 ea, $120.

Four 12' 4x4 $ $15 ea, $60.

My total outlay for that thing was about $250 but that was 20 years ago, figure closer to $350 now, it blows your budget but it's so much more than just the one thing, so your money is working harder than you think.

Nothing is completely safe. Splinters, nails, etc. The sooner your kids learn these important lessons in a relatively safe environment like the back yard, the better they will be able to apply them in the larger, wilder world. I'm not joking.