You are standing in the Great Hall. Tap anywhere to walk there, drag to look around, and open the numbered points to read the story of what you are looking at. On a keyboard you can also walk with W A S D or the arrow keys.
Use the W A S D keys or the arrow keys to move, and drag with the mouse to look around. Tapping anywhere in the room walks you to it. Press Tab to leave the model. Every point of interest is also listed as a button after the model, with its full text, so nothing here is only reachable this way.