Prompt: Write a short story about a man who discovers a magical portal

It was a cool autumn day, and my relative was out of town on business. I decided to take a walk through the local park. As I walked, I noticed a strange looking rock in the center of the park. I had never seen anything like it before, so I decided to take a closer look.

As I got closer, I could see that the rock was actually a portal. I stepped through, and found myself in a magical world. The trees were tall and green, the flowers were in bloom, and the air was warm and tropical.

I wandered around for hours, exploring the different villages and forests. I even found a hidden castle. I spent the whole day just wandering around, and when I finally returned home, I felt like I had been away for days instead of hours.

The next day, I went back to the park and discovered that the portal had disappeared. I guess I was supposed to come back another time. I hope I can find that portal again sometime.