This is a fascinating interview with landscape architect Michael van Valkenburgh (conducted in association with the BMW-Guggenheim Lab). We've been spending a lot of time in our lab of late trying to figure out what works and what doesn't work in urban greenspace. We're working at the level of neurons and psychophysics. It's great to hear some important truths from a master practitioner. I love what he has to say about the importance of hills. There aren't many where I live.