The Ballard Branch runs a close second here for one particularly striking feature: Its ceiling is built of thin wooden beams, while at the front of the large, airy space there's a round meeting room, the metallic walls of which curve up to a point. It looks very much like the prow of a ship, with the nearby wooden slats suggesting rows of oars, an homage, intentional or not, to Ballard's Scandinavian seafaring roots. But just edging it out is the beautiful Capitol Hill Branch, an even more theatrical space. The huge windowed back wall is even grander than Ballard's; it makes the brick building next door look like you're seeing it on an IMAX screen, and it grabs your attention first when you walk in. But turn around (as Gertrude Stein said, "I like a view. But I like to sit with my back to it") and notice that the vine-covered metal gridwork that covers the library's exterior extends inside the space, with plants lushly trailing over the walls and railings. Industrial chic meets rain forest. The Ballard Branch is famously "green," environmentally friendly in its construction and maintenance, while the Capitol Hill building is literally green, inside and out.—Gavin Borchert Ballard Branch, 5614 22nd Ave. N.W., 684-4089; Capitol Hill Branch, 425 Harvard Ave. E., 684-4715; www.spl.org.