505 Marquette Avenue NW (originally known as the National Building) is a high-rise office building located at 505 Marquette Avenue NW in Downtown Albuquerque, New Mexico.

It is 238 feet (73 m) tall and has 18 stories, the lowest six of which are occupied by a parking garage.

[7] The exterior walls of the parking levels are molded concrete with an open grillwork pattern of stylized quatrefoils inspired by Moorish architecture.

[8] The upper floors have recessed rectangular windows arranged in a simple grid pattern with beveled surrounds.

At the ground level, the exterior walls are battered masonry punctuated by narrow paired windows on the south side.