• Click a photo to fly to it
• Drag a box around part of the scene for a close-up
• Right-drag or Option-drag to look around
• Middle-drag to slide, wheel to move forward/back
• W A S D / arrows to walk, Space / Ctrl up/down, Shift slow
• B step back, R reset, Backspace / Enter history
• G switch point cloud (2007) / 3D Gaussian splats; in splats, P photo on/off, C cameras on/off; in point cloud, N overlays the new SfM points (red)

Port of the 2007 Java applet from Photo Tourism (Snavely, Seitz, Szeliski, SIGGRAPH 2006). Photos from Flickr.