On Tuesday, we featured the 124th challenge to see how well you know the Metro system. Here are the answers.

This week, we got 26 guesses. 10 got all five right. Great work, Christopher Deal, J-Train-21, ginger, AlexC, Brian J, Solomon, Manny, MtPDC, Tom A, and Greg Jordan-Detamore!

This week's theme was that all stations featured were served only by the Red Line. 9 of you figured that out.

Image 1: Grosvenor

This picture shows the northern portal at Grosvenor. Few outdoor stations have a tunnel portal directly adjacent to the platform. Grosvenor is one. This station is distinguishable because of the terminal supervisors' booth located at the northern end, necessary because of the Grosvenor turnback.

18 of you knew this one.

Image 2: Dupont Circle

The second image shows the plaque identifying the art located at the northern entrance to Dupont Circle. The poem etched into the granite around the rim of the station entry is called “The Dresser” by Walt Whitman. If you are familiar with the poem, this one should have been easy.

22 of you got this one right.

Image 3: Rockville

The third image shows the eastern wall at Rockville station which separated the Shady Grove track from the MARC Washington-bound platform. At top center, you can see the top of the MARC platform elevator.

14 of you figured this one out.

Image 4: Bethesda

This picture shows one of the escalators in the Bethesda Crescent building leading to the Metro entry. This building is on the east side of Wisconsin Avenue, and a tunnel leads from the lower level of the building's lobby to the Metro entrance. The lobby serves as a secondary public entrance to the station during certain hours.

Through the glass, you can also see the old Chevy Chase Bank headquarters building, which might have also been a clue.

20 of you guessed correctly.

Image 5: Shady Grove

Image 5 shows directional signage in the mezzanine at Shady Grove. The clues here included the pylon itself, simply directing people east and west, rather than to a specific street or destination. The location of the skylight above and the fare machines on the far wall are other clues. Also, as AlexC noted, the blue plywood wall that has been installed for construction of the escalator canopy is reflected on the pylon.

Several of you were inspired to guess Rockville because of the bus signage visible in the background, directing you to the Q1 and Ride On 46. This was unintentionally insidious. There are actually two stations served by the Q1 and the 46, with the other being Rockville. However, the 46's service to Shady Grove is limited, and I didn't realize that bus timetables don't show Shady Grove as a timepoint. However, the page for the 46 does include Shady Grove as a terminal.

While some of you note that we generally don't feature the same station more than once, you are correct. However, that's not actually a rule, and we have indeed featured a station more than once in a week before (and might in the future). You should go based on the clues presented, and not assume a station can't be featured more than once.

15 of you came to the correct conclusion.

Great work, everyone. Thanks for playing! We'll be back soon with challenge #125.

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.