Cities consist of many communities tied together by proximity, infrastructure and networks. But what happens when some communities are overlooked, when neighborhoods are gentrifying or otherwise going through changes that may not necessarily be in everyone's best interest? How do you prevent this from happening — or how do you deal with it when it does? Place-based philanthropy can ensure the sustainability of urban development efforts by providing long-term strategy, mobilizing patient capital and connecting funders with grassroots community leaders. In the Northwest, I recently visited three extraordinary urban sustainability projects that demonstrate the power of place-based philanthropy as a convener and catalyst: Yesler Terrace in Seattle, Living Cully in Portland and the Puyallup Watershed Initiative in greater Tacoma.