Conference description from organizers
From the conference site: "Sightline Institute and local pro-housing group Portland: Neighbors Welcome are excited to host YIMBYtown 2020 this April, in the wake of some major housing wins. This summer, Oregon became the first state to legalize middle housing statewide, and Seattle passed the nation’s best ADU policy. There has been more inspiring progress on housing in the Pacific Northwest and around the country, including Oregon’s passage of anti rent-gouging protections, Austin’s plan to unlock all neighborhoods for below-market homes, and Minneapolis’ triumph making space for more neighbors by legalizing triplexes citywide...
"YIMBYtown is the national convening of the pro-housing “yes in my backyard” movement. It’s a three-day gathering for grassroots community organizers, political leaders, educators, housing providers, and everyday people to identify problems, create solutions, and share resources and strategies. YIMBYtown offers inspiration, tools, and a network for those working to advance abundant, affordable housing and sustainable development in cities across the United States, Canada, and beyond.
"At YIMBYtown 2020: Fair and Sustainable Cities, we will spotlight and build on this year’s major wins, bringing successful housing campaign leaders to share policies, tactics, and lessons learned for local and statewide action. The 2020 elections also present a unique opportunity to influence the national housing policy agenda (we already are!): We will make sure that housing is a priority for ALL our elected leaders.
Lastly, we will focus on two (inextricably linked) issues that demand our attention: Climate change and Community stabilization."
Venue - Eliot Center
"YIMBYtown 2020 will be hosted by the Eliot Center. Located in downtown Portland, the Center is committed to hosting events that support sustainability, social justice, the arts, community, and education. The Center was founded by the First Unitarian Church of Portland, but the venue is nondenominational, includes no religious iconography, and explicitly welcomes all regardless of faith. The First Unitarian campus is also host to Outside In, a nonprofit that helps homeless youth and other marginalized people move towards improved health and self-sufficiency."
Nearby points of interest
I-405 Freeway 
I-405, directly west of the conference venue, is a short freeway that completes around Downtown Portland west of the Willamette River, between two junctions with I-5 at the Marquam Bridge and Fremont Bridge. It implemented a proposal for a downtown freeway loop made by Robert Moses, commissioned to design a freeway network for Portland in 1943. The freeway was constructed in the mid-1960s, utilizing a trench with extensive landscaping and frequent overpasses. Construction of what was then called the Stadium Freeway began in 1964, after $25 million in condemnations and land acquisitions, and largely consisted of excavating a trench between two city blocks. The majority of Interstate 405, between Montgomery and Johnson streets, was opened to traffic on February 25, 1969, while the Fremont Bridge opened several years later in September 1973
The Martha Washington Apartments
now owned by Portland Forward (former Housing Authority of Portland), offering a mixture of low-income and extremely low-income homes (< 60% Area Mean Income, and < 30%). It was formerly owned by Portland Women’s Union, for the housing facility formerly housed at their landmark 1917 Martha Washington Building (now Montgomery Court, Portland State University student housing) further south near PSU. PWU sold that building and bought the current Martha Washington Apartments building in 1970. "In January 1983, the Union accepted an offer from the Rajneesh Investment Corporation [Oregon based religious sect, the Rajneeshi's] for $1.4 million, with three Rolls Royces as collateral. The Union carried the loan and retained rights to the name, the Martha Washington. In 1986, the Rajneesh Investment Corporation sold the building to Multnomah County, which used it as a work-release center for county offenders until 2003. On June 16, 2010, the Martha Washington reopened as low-income housing run by Home Forward. https://oregonencyclopedia.org/articles/martha_washington_the_building/#.XWIz-JNKiV4.
South Portland/South Auditorium Urban Renewal District
Portland's first Federally-designated urban renewal district
"In 1955, a Mayor’s Advisory Committee identified the blocks at the southeast end of downtown Portland—bounded by Market, Front, Arthur, and Fourth—as suitable for a land clearance and redevelopment project. Civic leaders wanted to use new federal legislation that had expanded the Housing Act of 1949 to include what soon became known as “urban renewal.” At the same time, the city wanted to build an “exposition-recreation center” and/or coliseum, and the land south of the old Municipal Auditorium (now the Keller Auditorium) seemed like the ideal spot. A new facility would anchor downtown, they believed, and help bring spillover customers to struggling downtown businesses.
"The federal government agreed to designate the 84-acre area for urban redevelopment because the city certified that it was a blighted area. According to city data gathered to support the urban renewal designation, nearly one-third of that area’s 2,300 residents were over 60 years old and 1,000 residents lived alone in low-rent hotels and apartments. Some of its commercial buildings had been abandoned or turned to dead storage.
"In 1966, the city extended the project boundaries north to include twenty-six acres between Market and Jefferson Streets [Jefferson is one block south of Eliot Center conference venue]. The Portland Development Commission sold the expansion, which displaced 392 residents, as a way to clear out “Portland’s worst vice district.” In the formal Relocation Report, commission staff noted that “special attention will be focused on the elderly, single male individuals on limited incomes who may be experiencing health problems. Past experience has found these individuals to be of an independent nature.”
from Oregon Encyclopedia article by Carl Abbott.