Click the arrow to the left of "tags" to expand the menu to display dates, people, or places. It will make this:

Expand to this:

Once in a gallery, clicking on a photo will enlarge it, and clicking it again will bring you back to the photo thumbnail page. Hitting back on your browser at any time will return you to the year selection page.
                                                  20002001200220032004 Part 12004 Part 22004 Part 320052006
                                                  200720082009 Part 12009 Part 22010