I am looking for maps for Heroes III.

Yes, that's it, thank you.
If there's anything similar, I'd be glad to know.

It's not very clear what "similar" means. I can recommend a couple of maps that I liked from the ones I've played recently.
"Ksiaze Drakula" - an interesting Polish map where you can kick the butt of the forces of evil.
"Monster Island Ultra" - a map where it's dangerous to linger.