The northern end of the street runs under and through Pike Place Market.

[1] It was called "Seattle's best-known alley for its pedestrian environment and abutting shops and restaurants" out of all 425 alleys in the city,[2] and has been described as having a "European feel".

[3][4] The alley reaches a pedestrian-only area at the Harbor Steps development a block uphill from the Seattle ferry terminal, Colman Dock.

The Federal Office Building was built on an entire city block that was bisected by Post Alley until the early 1930s.

[7] Other notable entities on still-extant Post Avenue south of the Federal Office Building include Seattle Steam Company.