We've had lovely holidays, from just a few months old.
Are they the same as the child free city breaks with lazy breakfasts, long days sightseeing, and late night eating? No! But they're still huge fun.
We take toys, we take comfort items, we travel at a slower pace. From the age of 3 ish, holiday becomes defined (in our house) as an ice cream every day and chips quite a lot for lunch.
Sometimes we self cater - but if so that usually involves takeaways and lazy meals, or lunches in cafés and evenings grazing once they're in bed.
Other times we hotel it, but again we aim for big meals at lunch time, breaks up the day, increases the chances of post lunch naps, makes evenings quieter.
I always take weetabix or whatever the current breakfast fad is.
Ideally, we have a suite or a cottage or at least done means of separating living space and sleeping space. Don't mind sleeping in the same bedroom, do mind having to get into bed at 7pm!
We just take life slower. We stop at the local parks. We go and hunt out fountains with statues of little boys peeing, or find the little mermaid, or take lumps of cheddar with us to the local cheese tasting event so they've got what they want too.
It's a slower pace, and there's repetition built into it. We often go back to the same place year on year, so they know what to expect - finding the same walk to the lighthouse and making sure it's still there.
And we often go with friends. Good friends. The ones who have the sane parenting style, where we all know we can shout at any child who's about to push another child off a cliff. Where you have the same rules about vegetables and bedtimes, where the children can play with each other, and where you can crack open a really good bottle of wine once they're in bed, and take it in turns to do the early morning breakfast shift. Bit of a gamble the first time you go; I've other friends I love dearly but I'd never holiday with ever again. But when you find the right set, it's awesome.
One of the best baby/toddler holidays we do is camping with a large group. It's big enough that some people hang around the site all day, others go off on day trips, and no one is left out. Older children get squeezed into cars to go out, younger children get to go and feed ducks with whichever parent doesn't fancy the theme park, and there's always someone to herd a toddler or two when you really need to run to the loo but they'd rather be making daisy chains and mud pies. It's not easy, but it's great fun.