The Value of Dragonstone?

[Bollen46]

Dragonstone is a huge fortress located outside Blackwater bay that orignally was a valyrian outpost. But i´ve never understood why the Valyrians wanted that isalnd in the first place.

- I guess the Valyrians never saw Westeros as a threat since they were not united and Valyria had dragons
- it was probably not for trade reasons since King´s Landing was not founded so in that case The Arbor would have suited much better as an outpost for controll of the wine production and controlling the trade from Oldtown
- Stannis seems to hate the fortress for being cold and without fertile lands so it was probably not for colonization

Simply put: there´s nothing of value on the island to be found. And still they buildt a huge fortress that must have taken both alot of money and time to construct.
The only thing i can think of is all the obsidian that seems to be very effective against the others but the valyrians didn´t know them? And it would probably be tons of obsidian in the volcanos of Valyria anyway.

So what do you think, why did the Targaryens settle there?

[TallTyrion]

Didn't they tax the ships of Blackwater Bay? There's no King's Landing but Duskendale, Massey's Hook, the other Islands and whatever settlements in the future Crownlands would provide decent revenue.

[Poodle Pup From Astapor]

Yep, they used Dragonstone and Driftmark, ships and dragons to control and tax sea trade not just in Blackwater Bay, but in much of the southern Narrow Sea. A lot of money.

Arbor would be another good option, but you'd have to travel much further and then conquer it, and they probably didn't even know much about it at the time. It would've seemed too risky. And Arbor is probably less lucrative than southern Narrow Sea either way.

[Ibbison from Ibben]

Dragonmont is an active volcano. The Valyrians used volcanoes (The Fourteen Flames) in the magics. It is likely that Dragonmont was being developed as the Fifteenth Flame. Hardhome was probably being developed as the Sixteenth Flame until it blew up in everyone's face. (Dragonstone was settled by the Valyrians about six hundred years ago. That's the same time that Hardhome blew up.)