We usually have our kids wear Natives for long walking days. However, this last trip I grabbed a pair of Birkenstock-style sandals for my 4 year old (Cat and Jack imitation of Birkenstocks anyway at Target). They have that similar kind of double layer sole and a bottom that has ridges so they're not slippery, if that makes sense. I also brought Natives and a pair of New Balance sneaks to use on different days, as I knew she'd be walking a lot and figured a Cat and Jack sandal that was like $15 couldn't hold up. Turns out, the sandals were amazing and I didn't even take the other shoes out of the suitcase. The adults walked 10+ miles a day (closer to 13-14 some days I'd guess) and she probably walked 2/3 of the time and not a single blister or mark. I highly, highly recommend them!