How to Run a Marathon on a Rooftop

I haven't been cycling like seriously since 2020. Phil has cycled from Bristol to bar for a few times which is like maybe 30 miles round trip and he wants to do like 100 miles. He reckons himself a cyclist as well. He's gonna cycle from bath to bogna on his birthday. I'd love to run a marathon I'm trained just turn up. We could go and run a marathon on the road with no training but it's like sort of has been done by loads of people too easy. Imagine finding like the East Croydon set of rooftops you just run around all day until you hit the 26th. You know you're running under generators trying to