Game Of Thrones Season 7 Premiere: 9 Things You Might've Missed In 'Dragonstone'
8. The Opening Credits Additions

The opening credits of Game of Thrones are always worth sitting through, given they clue you in to where we're going that week (and just look great), but that's especially the case when major changes have happened or a new location is being introduced.
Dragonstone, then, has a couple of important pieces on the map. One is the return of Dragonstone itself, which hasn't been featured since Season 4, and now has the Targaryen sigil on it. Speaking of sigils, King's Landing remains Baratheon, even though Cersei Lannister has decked out her Throne room with a Lannister lion.
The biggest change, though, is with the addition of Oldtown. Here we get to see the Hightower - ruled by House Hightower, fittingly - which stands in the middle of the city. In a fun bit of mapception, we see an astrolabe in the middle of it, the same spherical objects that appear in the Citadel's library, and as part of the opening credits since the beginning.
The people who make the map envisage it as being made by a mad monk in a tower, keeping track of the events of Westeros and beyond. If they're indeed Maesters, then it means they're putting themselves in the map they've created.
On a final opening credits related note, this is the first time they haven't shown any part of Essos, since Daenerys has finally made it to Westeros.