The typical approach to recycling outdoors is to not provide the recycling option, which characterizes most town streets.
In Princeton parks, 35 gallon yellow recycling bins have been common. Though they work pretty well if paired with trash cans, their large openings make contamination with trash more likely.
A more expensive approach was tried at Turning Basin Park, where many pairs of wood-framed trash and recycling containers were installed for a total of $12,000. They're built to last, and won't walk away, but their subtle visual cues--particularly the similarly sized holes--are problematic. Contamination seemed minimal when I checked, but I have since heard they aren't working as well as hoped.