The phrase 'unique sight' is correct and usable in written English.
You can use it to describe something that is particularly interesting and attractive to look at or experience. For example, "The sunset over the ocean was a truly unique sight."
It's a unique sight in Europe.
A unique sight in Udinese's game against Lazio, as the hosts lined up in 11 different shirts – every player wearing a different one from the recent past.
The Lizard-Cuckoos of the Caribbean Basin are truly a unique sight, with reptilian features, well suited to their former genus name Saurothera.
The sun was setting as we headed back towards the ranch, but one more unique sight awaited.
The intensity of the waterfall combined with its lush surroundings is a unique sight.
However, San Franciscans witnessed the first great gathering of plastic bags in the form of at least 60 Bag Monsters on Aug. 12, and it was truly a unique sight.
Before the onset of winter, I was extremely privileged not only to visit the site and box, but also to witness one of Antarctica's most unique sights.
A unique sighting of a grey whale in the Mediterranean in May 2010 – the animal got as far as Israel – has overturned many preconceptions, with some scientists speculating that this much-hunted great whale – reduced to near extinction in the 20th century – is regaining ancient migratory routes.
Graham Elliott of the RSPB said it was a "surprising" but not unique sighting.
To preserve the unique sights and sounds which are usually inaccessible to the public, and which will be lost after the renovations, four artists were granted special access.
Writing for the Australian newspaper, disabled journalist Melanie Reid marvelled at the unique sights of Paralympic events: "80,000 people falling silent so that a blind long-jumper can sprint into her darkness towards the sound of someone clapping.
