The line

The Pike Place Market Historical District is a polygon with 30 corners, 12.827 acres of area and 1,101 metres of edge, drawn by Seattle Municipal Code chapter 25.24 and published by the city as overlay code PP in its zoning overlay layer. Every count on this site is that polygon answering yes or no.

MarketFrontPike Place Market ParkingNorth ArcadeMain ArcadeSanitary Public MarketFirst & Pine BuildingMarket Place TwoInn at the Market BuildingCorner MarketFairmount ApartmentsStewart HouseChampion BuildingPike & Virginia BuildingAlaska Trade BuildingLeland HotelLandes BlockFix BuildingGarden Center Building
The district as the city draws it, with every building outline OpenStreetMap holds inside it.

Nine acres or thirteen

The Market's own visitor page describes a 10-level, 9-acre Market. The city's district measures 12.827 acres. The difference, 3.83 acres, is the part of the district the Preservation and Development Authority does not run: privately owned buildings on First Avenue, Post Alley and Western Avenue that sit inside the historic boundary and answer to its rules without being the Market.

A reader asking "how big is Pike Place Market" gets a different number depending on which body is answering, and both are right about their own question.

What the boundary contains

LayerInside the lineIn the surrounding box
addresses215898
buildings896
parcels32215
trees25734
crosswalks991
publicart526
landmarks024
streetpark36175
garages236

The box is a rectangle larger than the district, from 47.607998 to 47.611068 in latitude and -122.344446 to -122.339687 in longitude. A thing counted "in the box" and not "in the fence" is a near miss, and the near misses are what make an edge visible.

How a point is decided

A business licence carries a street address and no coordinate. The address is normalised, matched against the city's Master Address File, and the resulting point is tested against the polygon by ray casting. 152 of 153 inside the line matched an exact house number; 1 matched the nearest number on the same street, within six doors, and are marked as such wherever they appear. 135 licences on the market's streets could not be placed at all and are counted nowhere.