If you haven't been back to Nationals Park or the surrounding Near Capitol Ballpark River Yards neighborhood since last year's Opening Day, here's what you'll see that wasn't completed on your last visit:

* 55 M Street - Right on top of the west entrance of the Navy Yard Metro station, at the head of Half Street, is Monument Realty's 275,000-sq-ft office building, which has been finished in the last few months and which will be home to Artomatic this summer. No office or retail tenants have been announced, although WBJ reported a few weeks back that Gordon Biersch may be eyeing some of 55 M's ground-floor space. The rest of Monument's Half Street site remains a large hole in the ground, with financing for the planned 350 residential units and adjoining hotel directly across from the ballpark nowhere to be found.

As for what's currently underway, there's the first phase of townhouses at Capitol Quarter (where the first residents will move in this month and where work will continue into next year), the 200-unit Velocity condo building at First and L, and the 440,000-sq-ft office building at 1015 Half Street (which will be completed in 2010 but will already be cursed for obscuring the view of the Capitol dome from some seats in the ballpark that had it last year). There's also construction continuing at Diamond Teague Park, right across from the ballpark's grand staircase, but the somewhat optimistic timeline of having the water taxi piers completed by Opening Day has now been revised to "midseason."

Work had begun on rehabbing the brown-and-white Pattern/Joiner Shop at the Yards last year (which folks walking to the ballpark from the Nats Express drop-off will see), but financing problems brought the work to a halt early in 2009, and Forest City continues to look for money to restart the project.

The most prominent structure that's disappeared in the past 12 months is the former WMATA bus garage on Half Street just across from the subway entrance, demolished two weeks ago to make way for Akridge's planned 700,000-sq-ft mixed-use development, though that project won't get underway before 2010. (The south end of Akridge's Half Street land is where the [not-a-]beer garden may appear later this summer.)

But, as has been written about extensively elsewhere, as of now there's no new places to eat since last year (though a deli is coming to Third and K in May), and most likely no additional projects will get underway before next year.

So, study this little guide and amaze your friends with your knowledge of what's what as you look at the ballpark's surroundings.