TOPSHOT - Military aircraft enthusiasts watch as a United States Air Force (USAF) F-15 fighter jet as it travels at low altitude through the 'Mach Loop' series of valleys near Dolgellau, north Wales on June 26, 2018. The Mach Loop valleys, situated between Dolgellau and Machynlleth, are regularly used by the military for operational low flying training which can take place as low as 76 metres from the nearest terrain. / AFP PHOTO / OLI SCARFF