NGC 6506 (also ESO 521-SC6 and OCL 16) is an open star cluster located in the constellation Sagittarius.
The cluster was discovered by British astronomer John Herschel using a 47.5 cm (18.7 inch) f/13 speculum reflecting telescope at the Cape of Good Hope on the 29th July 1834.
Right Ascension 17h 59m 53.4s, Declination -24° 41' 07"