Flight 93 Memorial
The Flight 93 National Memorial is built on an old coal strip mine. The gold colored pools along Approach Road in the National Memorial are Acid Mine Discharge, a highly acidic chemical caused by pyrite rock exposed to rain water as part of the former coal mining process.
https://www.arcc.osmre.gov/programs/tdt/flight93.shtm
Taken on Saturday October 6, 2018 at Flight 93 National Memorial.