We are going to see the sights.Which of these is correct? Actually, either one could be. Let's look at all three words with some help from our friends in Stargate SG-1 and Hawaii Five-0.
We are going to see the sites.
The most common of the three words is sight, which can be a noun or verb and always has to do with using one's eyes, literally or figuratively.
sight - noun
1 the faculty or power of seeing
"Jack, quit taking my glasses," Daniel grumped. "You know my sight is no good without them."2 a thing that one sees or that can be seen
"All right, campers, you can move out but stay in sight," Jack warned.
Major Davis pointed out to General Hammond, "Let's face it, in Thor's sight, SG-1 can do no wrong."
Grace bouncing down the hallways to see her Danno was a welcome sight at Five-0 headquarters.3 a device on a gun or optical instrument used for assisting a person's precise aim or observation
The tourists seemed to think Hawaii was nothing but sights to rubberneck, to Max's annoyance as he tried to get through traffic to the crime scene.
Jack used the sights on his telescope to get it aimed towards Mars before peeking through the eyepiece.sight - verb
1 [transitive] manage to see or observe (someone or something); catch an initial glimpse of
"Have you sighted the Jaffa patrol yet?" Teal'c whispered.2 [intransitive] take aim by looking through the sights of a gun or [transitive] adjust the sight of (a firearm or optical instrument)
Sam sighted carefully down the barrel before squeezing the trigger.
Daniel spent some extra time in the armory sighting in the Berreta to make sure he was accurate.
Sight is most commonly confused with site, which is a word that can also be a noun or verb but which always has to do with location. Its root is the Latin word situs—local position—which is also the root for situation.
site - noun
an area of ground on which a town, building, or monument is constructed or a place where a particular event or activity is occurring or has occurred
General Hammond had two teams out scouting planets for a new Alpha Site.site - verb
No matter how many times Steve visited the USS Arizona memorial, he never lost his reaction to being on the site where so many sailors lost their lives.
[transitive] fix or build (something) in a particular place
Sergeant Siler surveyed the damage. "We should site the Xenobiology labs farther away from commonly used corridors."
Site is often mistakenly used in place of cite, which is only a verb, referring to a quotation or summons. If the noun form is needed, it is citation.
cite - verb
1 [transitive] quote (a passage, book, or author) as evidence for or justification of an argument or statement, esp. in a scholarly work [as an example, as official praise, or for a legal argument]
Daniel's entire department knew that if they cited Budge in a translation, they'd better have a second reference to back it up.2 [transitive] summon (someone) to appear in a court of law
Steve looked over his new partner's file. The man had been cited for bravery three times in New Jersey; his skills had definitely been wasted at HPD.
Jack leaned over and whispered to Daniel, "So, can you cite any Nox legal precedents? Do the Nox even have law libraries?"
Chin gave up the search. "This guy's never even been cited for jaywalking."
If the word you're using is a noun, you can narrow it down to two choices. Let's go back to the examples from up top:
We are going to see the sights.If you are acting like a tourist, you are going to see the sights. Sightseeing is what you do on a tour. If you are an architect or contractor, you are going to see the sites. Likewise if you are visiting locations where specific things were placed or events occurred, or even the location on the Internet where a particular person or organization has a presence. Of course, if your building project is a resort, you might visit the site to find the best vantage point for the sights! Or you could visit the sites of historic Buddhist temples in Thailand to enjoy the sights. Fandom Grammarian zellieh offers the mnemonic: "Is the campsite within eyesight?" If it's about the location, it's site; if it's about seeing it, it's sight.
We are going to see the sites.
If the word you're using is a verb, check to see whether the meaning has to do with eyesight or aim, location, or quotation or legal summons. Note the difference in these three examples:
Jack decided to site the tents to the west side of the clearing for the best morning sun. It also meant any visitors coming from the town wouldn't sight the tents through the thick undergrowth in that direction. Rumor had it the town's legal system was annoyingly bureaucratic, and he had no desire to have local law enforcement cite the tents for violating whatever arcane public camping laws they might have.
The differences in meaning between the three words are fairly distinct. Once you can separate out the seeing uses from the location uses from the citation uses, you should be good to go.
Definitions from New Oxford American Dictionary