What is light green pipe buried in courtyard?

The light green pipe buried in a courtyard is likely a type of drainage or irrigation pipe, often made of PVC or similar materials. It could be used for systems such as stormwater management, landscape irrigation, or to direct water away from foundations. If it's not connected to any visible fixtures, it may be part of an older or unused system. It's best to consult with a professional if you need to identify its specific purpose or determine if it poses any issues.