Hey! I only had 5 hearts at the time and had yet to even set foot in a divine beast, but I was successful in gaining access to Hyrule castle and found a flame blade. I entered from the west side of the castle by way of the moat. One of the massive pillars around Hyrule castle has a raft docked...
Good idea for going to the bridge first, It's narrow and easy for the programmers to put a triggered cutscene in that location, it might further the plot or, seeing as it is a location identified in past games, might provide clues about the history and placement of the game in the series timeline.
I'm relatively certain that many of you have done a fair amount of time watching videos of the E3 demo, and I'm sure that many of you may have seen a far off landmark that piqued your interest. So I have to ask, is there any particular spot that you feel drawn to that you'll want to check out...