Very old dos game

i know that this sound kina silly but i was wondering if any know the name of a game where you have a guy and you dig tunnels, you can like make underground water passage if you dig where it has raind. i also remember that you had to destroy a castle or something, i was like 8 at the time taht i playd it so i don't remember it but i do remember that it rocked!

Thanks, in advance

And omfg that **** is so cool!!!!! Thanks for telling me about it. It's so **** cool