Smaller/boutique hotel with kids club?

I’m looking for a unicorn. We’d like to travel with our 3 (almost 4) year old this winter. We like smaller boutique hotels where we can actually get off the property and experience local culture. But I’d also love a kids club so I can sit by the pool and relax for part of the trip. Does something like this exist?

(FWIW, kiddo turns 4 in March 2026 and we can possibly wait until after his birthday if he needs to be 4)

We’re also on a budget – we’d like to keep hotel under $400/night (more if it’s AI). Ideally somewhere with direct flights from Boston, but that’s not necessarily a deal breaker.

Thanks!!