I believe this is a ‘crimson cloud’ hawthorn tree. The photo was taken during a lovely June weekend in Sheffield, South Yorkshire. I believe the actual location is near a small park called Sheaf Valley Park which is between the train station and the Cholera Monument Grounds. It was a lovely spot on a lovely weekend before I went into the Peak District.

https://en.wikipedia.org/wiki/Crataegus_monogyna

https://en.wikipedia.org/wiki/Sheffield