In my GURPS Dungeon Fantasy game, Felltower, the PCs are repeatedly delving into and raiding a singularly large megadungeon.
At the start of each session, after we've dealt with in-town activities, spending points, general logistics and bookkeeping, the PCs head up to the dungeon.
At that point, I give the same spiel:
"You head out of the North Gate, across the Stone Bridge over the Silver River, over to Stericks Landing. You pass the statue of Baron Sterick the Red on horseback, his sword and axe upraised, and pass through the slums to the barren track up the side of the mountain."
That's pretty much, word-for-word, how I say it each time.
One of my players commented that the statue of Sterick the Red, which I mention every session, must be important because I mention it every session. That might be true - but I also specifically mention leaving the North Gate, crossing the Stone Bridge over the Silver River, the slums, the path, and so on, every session. Partly it's because the details might be important, but also because I find the forumalaic repetition a good sign that things have begun, and to get things off on the right foot. I had a martial arts instructor - who also trained one of my players, who finished every class with the same line. Ritual is useful, and I find it is useful in gaming, too - whether or not it's in-game important or not.
The use of a ritual signals something to the players. For my starting ritual, it signals the adventuring has begun. You've left town. It's too late to buy a potion. It's too late to spend some points on learning new skills. It's way too late to engage a sage and ask some questions. You're on the road. We've begun.
Similarly, it can signal an end to the game session. Or that we've transitioned from one part to another. One GM I used to play with would end any scene-setting description with, "It's your scene." Until you heard that, you knew to sit and listen (carefully, presumably) and then it was your time to act. No point in interrupting him, because what was being told to you was how things were, not a cue to act. It was a helpful ritual in his games.
So while the statue of Sterick the Red on horseback, with his sword and axe upraised, might be very important, it also might just be part of the ritual. It's not clear to the players, but what is clear is that the game is starting once that speech is going. I highly recommend a "starting ritual" to signal when it's time to end the bookkeeping and start the dice hitting the table.