NGC 6756 (also Collinder 398 and OCL 99) is a magnitude +10.6 open star cluster located 4,900 light-years away in the constellation Aquila.
The cluster was discovered by German-British astronomer William Herschel using a 47.5 cm (18.7 inch) f/13 speculum reflecting telescope at Slough, England on the 21st August 1791.
Right Ascension 19h 08m 42.5s, Declination +04° 42' 18"
