Most people with good ideas are not willing to share theirs. Look around you for inspiration, or look at other maps to find something not done before.
I have some ideas: Make an infection map on sandtrap with 300% speed and 50% gravity, than make the zombies invisible and start them with lasers and hammers. It's never been done before. On a serious note..ideas no, but inspiration I can give you, or at least tell you how to find inspiration. Looks at book titles, song names or lyrics, news topics, your favorite words. Than base a map off it
here's one make a map that is a spiritual successor to hang 'em high I'm just to lazy to make it so go for it and if you do make this at least tell people where the idea came from.
I'm making a map with an idea, so I'll give you one as long as you give me credit for the original idea. I'm making a house, no exits. I'm making a few floors. It's raining fusion coils on the top floor, but that's also where the power weapon is. Try it.