sight to behold

(be) a sight to behold AND (be) a sight to see (spectacularly beautiful || incredibly ugly or revolting, etc.) — глаз радуется; любо-дорого посмотреть (одобр., ирон.); загляденье; зрелище, на которое стоит посмотреть; ≅ отворотясь не налюбуешься (неодобр., ирон.)

Example 1: Standing near him now, she was a sight to behold, tall in the saddle, her dun-colored uniform fitting loosely on her big-boned, lean frame. He was beguiled by her uniform, her round, flat-brimmed Ranger Stetson hat, her gun, and her badge. Her plain face so easily adopted that no-nonsense bearing. He'd seen her laugh, but soon after, her face would reassume that stern countenance, that command presence coveted by cops. (2009)

Example 2: ()

Also
be a joy / pleasure/ marvel /wonder etc to behold (something that is enjoyable/marvellous/wonderful etc to watch)

Example: The team’s performance was a joy to behold. (MM)

Related vocabulary:
eye candy
a sight for sore eyes
a treat for the eyes
easy on the eye
pleasing to the eye
[глаз радуется]
[любо-дорого смотреть]
[глаз не оторвать]