Has anyone visited Monte Tamaro with their children? If so, would you recommend it? Looking for something to do as a day trip from Lake Como in June with our four children ranging in ages from 11-18.

MONTE TAMARO - GRADICCIOLI - MONTE LEMA
I love this area and know everything about it.
We walked once from Alpe Foppa gondola station and another time from Alpe Neggia bus station to Monte Tamaro and then to Monte Lema when our kids were much younger than yours.
The access from Como is easy (TILO train to Rivera plus gondola to Alpe Foppa), but time consuming from more remote places like Menaggio or even Bellagio or Varenna.
Count 1 hr from Como up to the gondola station at Rivera, 1 3/4 hrs from Menaggio (via Porlezza), but 2 1/2 hrs from Varenna (train changes at Monza and Lugano).
May be your kids will prefer to stay all the time in the adventure park (instead of hiking to the top of the mountain).
Excursions and walks in Ticino - Monte Tamaro

We have a car so we could drive if that would be easier and faster.

kids should love it!

https://www.google.com/search?q=mont...w=1280&bih=633

I would come by car. As you don't stay in a hotel in Canton Ticino, you will not get a Ticino Card for free and will have to pay for the use of trains and buses.
https://www.ticino.ch/en/ticket/part...transport.html