There are some things that you pass in your day-to-day that you fail to notice. Much of the urban landscape becomes backdrop - with bits and pieces that stick out and make you say "wow." Philadelphia has such a piece in its 8th Street subway station. These wall-mounted structures offer seating, leaning/shelf for tending to one's bag, all while being a striking visual dance of bent metal. They serve several purposes all while keeping the station easy to clean (wall-mounted = ease of floor cleaning) and I would imagine the pieces themselves are quite easy to maintain themselves with their shiny metal and all. These benches address security concerns as well by being open (for visibility for items underneath) and providing decent seating surface area while deterring unnecessary loitering without resorting to the "armrest" insert - a common and unsightly tactic.
In short, these benches address all of these concerns when designing for public spaces [security, maintenance, and user experience] and do so gracefully. Important to note, there are several designers who address this concern of urban seating - a particular designer was recently featured on DesignBoom and 3 of his pieces are shown below - compare them to the 8th Street benches and let me know what you think.
alexandre moronnoz: urban seating: Via DesignBoom
'muscle', 2009 by alexandre moronnoz
steel, zinc coat & heat-lacquered paint finish
retified timber with no surface treatment, external resistance. digitally milled.
steel, laser-cut, folded & welded. zinc electroplate & epoxy paint finish