One of my favorite places for poetry prompts over the years has been Poets Online. Their ‘current prompt’ is updated about once a month and is always a challenge.
An interesting aspect of their web prompt is the invitation to send in poems written from the current prompt. About a week to ten days after the submission deadline a page, with the prompt along with the poems chosen for publication, is posted as 'Read the Newest Poems." These are eventually relegated to their place in the "Archives."
The current prompt is here. Last date for submission is a week from today - January 28th. Am I up for it? Are you?