On Tuesday, we featured the 123rd challenge to see how well you know the Metro system. Here are the answers.

This week, we got 16 guesses. Nine got all five right. Great work, AlexC, Christopher Deal, Peter K, Solomon, AlrFfx, Mike B, Ginger, MtPDC, and Stephen C!

This week's theme was that all stations featured were served only by the Green Line. Eight of you figured that out.

Image 1: West Hyattsville

The first image shows a view of the canopy at West Hyattsville station. This is one of Metro's few unique stations. No other station has an architectural style like this one, though West Hyattsville does share design motifs, like the same tilework, liberal use of exposed concrete, and globe lights. Solving this one required you to recognize the unique canopy style, including the crossbars holding it up. Additionally, this is one of only four Metro stations that are outdoor and have side platforms. Of the others, Cheverly and Eisenhower Avenue share a modified Gull I canopy design and the roof over Arlington Cemetery isn't a canopy, but is the wide bridge carrying Memorial Drive over the station.

13 of you knew this one.

Image 2: Navy Yard

The second image shows the Half Street entrance to Navy Yard. This station is a fairly typical island station with the waffle vault design, but it does have some unique features pictured here. When the station was rebuilt a few years ago in preparation for the new Nats stadium, the fare control was moved up to street level. This is the only waffle station where a picture from this angle wouldn't show faregates and the station manager's kiosk. There is also a knockout panel on the far wall which was left for the installation of a future street entrance. Federal Triangle has a similar kockout panel, but that one would be obscured by the platform elevator from this vantage point. We featured both knockout panels in week 65.

12 of you got this one right.

Image 3: College Park

The third image shows a view of the canopy at College Park from the adjacent parking structure. Few "general peak" stations have parking structures directly adjacent, so this one should have been easy to deduce.

14 of you figured this one out.

Image 4: Naylor Road

The fourth picture shows the canopy at Naylor Road. This "general peak" station has a slightly modified canopy. Like its neighbor to the south, Suitland, the skylight here is very shallow. At most general peak and high peak stations, the skylight rises at a 45-degree angle relative to the roof. Here, it's noticeably shallower. The beams supporting the canopy that run parallel to the tracks are also a clue, since they taper at the end of the canopy, similar to the treatment of the beams at White Flint.

Additionally, the globe lights here are mounted on conical fixtures, as opposed to the standard thin tube mounts. This is more typical of the southern Green Line extension stations.

14 of you guessed correctly.

Image 5: Congress Heights

The final image shows one of the station entrance pavilions at Congress Heights. Only three stations feature this type of escalator canopy: Columbia Heights and Georgia Avenue, which opened in 1999, and Congress Heights, which opened in 2001. Both Columbia Heights and Georgia Avenue are surrounded by dense development, so the absence of other buildings visible here means this must be Congress Heights, which is less developed. Some of you also mentioned using the communications tower in the background to confirm your suspicions.

14 of you came to the correct conclusion.

Great work, everyone. Thanks for playing! We'll be back soon with challenge #124.

Information about contest rules, submission guidelines, and a leaderboard is available at http://ggwash.org/whichwmata.

Matt Johnson has lived in the Washington area since 2007. He has a Master’s in Planning from the University of Maryland and a BS in Public Policy from Georgia Tech. He lives in Dupont Circle. He’s a member of the American Institute of Certified Planners, and is an employee of the Montgomery County Department of Transportation. His views are his own and do not represent those of his employer.