Climbing with young children (<5yo)?

My sister's family is visiting this summer and they've got young kids (under 5) that love to climb up stuff so I want to take them all out somewhere to try scrambling around outdoors (on a rope). There's plenty of easy (<5.6) climbing around the front range but most of it is going to be on features large enough to be insurmountable by a young child. As a result, I'm trying to come up with a list of the most promising options for us to take them to so I can scramble up, throw a TR up, and everyone can take a lap. 

Right now my list of leading options is:

- Supremacy Rock in Eldo (the little slab by the west parking lot under The Web)

- The Gazebo/First Flatironette in the Flatirons

- Sunshine Slab on Turret Dome

- The various slabby 5.4/5.5s at Staunton (pitch 1 of Growing Pains at Hemingway Wall, most of the pitch 1s on Park View Dome/Ranch Hand, etc)

- The 3 Sisters slabs

Most of these are just the slabbiest climbs that I know of - anyone have good suggestions for steeper routes with 'kid sized' features (IE many options for holds that smaller arms could use)? Any other routes that you've taken your young kids to and they've had a good time?

Whale's Tail in Eldo has a fair bit of low angle, <5.6 stuff. Movement Englewood (and possibly some other Movement locations) has bouldering problems that are designed for kids, and they might have some roped climbs that are appropriate for kids, too. This would be a good rainy day/evening option. Keep in mind that kids under 5 have a fairly high center of gravity (that's why they ski the way they do), so what looks shabby to you is probably going to look quite steep to them.

Movement Golden and Centennial have the best rope options for little ones- Englewood has a great kids area, but sometimes the holds can be a bit too far apart for the wee ones.

Id be super flexible on whether they’ll climb- or for how long. Sometimes our kiddo will climb for hours, sometimes he’ll throw his shoes across the gym. Depends on the mood.

Any kids under 6 or 7 have to have a full body harness, btw- they’ll slip out of a sit harness quite easily if they tip backwards.

The gym is a good idea as a backup plan! I forgot that we get a wild number of guest passes/first time visitor passes. Hoping to get everyone into the great outdoors though if possible.

We're definitely getting them full body harnesses as the first order of business. There's a gym not too far from where they live out east so they could always take them home. I'd planned to buy them, but is there anywhere you can rent them (or shoes)?

If we're talking gyms then ABC Kids Climbing in Boulder is a great option. They have bouldering areas for little ones and autobelays with full body harnesses. My 3 year old went to a few classes there and loved it. Check the open gym hours though as it depends on whether they're running camps or not.

When my kids were teeny tiny, I used to throw a rope off the roadside outcropping just downhill from the Monkey Traverse on Flag. There's also a great spot for a little-kid toprope if you hike uphill maybe 30 yards past the First Overhang problem and look to your left: scramble up a 5.0 slab and hang a line from a little tree. It's definitely not an established climb, just an accessible, easy, low-angle place to hang a rope (and then you can get ice cream on Pearl Street). Now my teeny-tiny kid is in college and is leading outdoor camps for ABC this summer, but I think they start at age 7: https://www.abckidsboulder.com/home-2/outdoor-summer-camps/ 

I haven't actually been to this crag in BC, but the idea was kid focused.
https://www.mountainproject.com/area/108182017/turtle-rock-a-crag-for-kids

The east side of Tunnel 1 in Clear Creek has an area with some easy routes (not sure specifically about "kid-sized" features) that you can scramble up and use a few sets of bolted anchors to set up TRs on. They aren't listed in this section of MP, but they are right along the trail just past the Creek Corner route if you're walking from the parking lot. Here's some info from the CCC guidebook:

Also, just a heads up that the west trailhead parking lot at Alderfer/Three Sisters is closed for construction for the rest of the year, so might be kind of a mess up there for visiting over the summer.

Check out "Campground Rock" at Staunton State Park. It's not on MP, but it is used often for kids climbing events, including Marmot Fest. It's like .3 miles from the Meadow Parking lot and it is super easy to hike up and set up top ropes using bolts and/or trees. The is a split rail fence around it, benches and a nice flat area for the kids to play. It is ledgey so I've found it's easy to encourage the little kids to the top, but can be hard to get them down. Ie, they get stuck on the ledges and can't figure out how to sit back in the harness.

Bear Creek's east side has some of the best chill climbs I've seen for kids. mountainproject.com/v/12077…

New one, developed with kids in mind as a potential user group: Wild Thing Wall 

A bit of a hike (1.25mi), but if you are considering the first flatiron than this should be no problem. Fairly easy walk-up TR access for most routes, and anchors are generally placed in a way that the rope isn't rubbing on the rock too much. Flat belay/staging area and great views at the top. There's a summit register on an unnamed peak (Peak 8659) as well that woud be fun to sign with the group (please bring a pen, the current one in there is on its last limb). There's plenty of harder climbing (up to hard 12) as the immediately surrounding crags if the kids get bored and the adults want to play. Grab food at the new mexican restaurant at the Bailey turnoff to complete the day.

If you do make it out, would love to hear feedback on how it went for kids/what you think the "minimum height to ride" at the crag would be. For the most part, it's like climbing in the flatirons, but on granite, and pretty well-bolted.

The climbing on Growing Pains is great for kids but the approach and base is not. For Whom the Bell Tolls is a kid friendly option.