Camp Half-Blood is a fictional place created by Rick Riordan as a safe haven for demigods - children of Greek gods. While there are real places that might inspire the setting (like summer camps in the woods), Camp Half-Blood is a magical and mythical place built specifically for the story.
However, the idea of a secret place for demigods is a fun and imaginative one. Many fans love the idea of a place where they could belong and learn about their heritage. Maybe one day, we'll see a real-life camp inspired by Riordan's creation!