This is our favorite Seattle stadium that never was. Like so many big ideas in Seattle, this one came from the early ’60s around the time of the World's Fair. Construction magnate Howard S. Wright, Jr. proposed a domed stadium that would float in Elliott Bay on pontoons at the end of West Harrison Street. At the cost of about $22.4 million, it would hold 50,000 for baseball games and 65,000 to 70,000 for football games. The monorail would have extended past Seattle Center to meet it. Voters didn't support a $15 million bond proposal, the Seattle City Planning Commission issued a report advising against the project, and that was that.

Now, Seattle quibbles about whether or not to put affordable housing on the former military land at Fort Lawton, but once the city considered putting a stadium there. According to Sports Press NW, the city was looking at the spot for a stadium as early as 1938 as the military considered declaring the land surplus: “The fort had the space for all the parking a 60,000-seat stadium would need with room left for an 18-hole golf course and a scenic, shoreline park.”

The military would eventually give some of that land to the city in the 1970s, which became Discovery Park. The rest of the base closed up shop in 2005.

Around 1967, initial plans were made for a domed stadium on the 80-acre tract of land just north of Pier 91 in Interbay along 15th Avenue W. This was one of the potential options for the 1960s King County stadium proposal, but in the end it just didn't have the access or parking capabilities as some of the other proposals.

Another one of the proposed stadiums in 1967, this one offered easy access to the freeway and was close enough to downtown to make it easy for businesspeople to head over. It was one of the five finalists but ultimately lost out to the Kingdome, which was closer to city center.

South Park almost became the once-future home of the Seahawks and Mariners. A proposed stadium between W Marginal Way & Route 509 at S Director Street was one of the initial finalists for the King County stadium proposal that ultimately went to the Kingdome. The South Park site was initially seen as one of the favorites due to it's ample space for parking.

In 1963, Pacific Raceways had big ideas out in Kent, proposing a sports complex with an 80,000-seat stadium. The venture would have been privately funded and at least one stadium committee thought it was the cheapest and best site for the impending stadium. But Seattle wanted its Seattle stadium in Seattle, and that was that. Pacific Raceways still operates a track out of Kent, though.

The Riverton area, now part of Burien, almost had a shot at the Mariners and Seahawks during the King County domed stadium proposal chase of the 1960s. The plans were eventually scrapped due to the $50.5 million price tag.

Though it's unclear where exactly they were thinking, a proposal in the 1960s to put a domed stadium in Factoria made a lot of sense. It likely would have been right at the I-90 and I-405 exchange—around where Factoria Mall is—an ideal spot for commuters. It was one of the 15 finalists for the King County domed stadium, but it was eventually eliminated before the final five.