Welcome to Wilson Park in Downtown Menomonie. Wilson Park is the home to Menomonie's Farmer's Market from 8-1 on Saturdays and 11-6 on Wednesdays from spring to fall. It is also the performance space for the Ludington Guard Band who uses the band shell on Tuesday evenings throughout the summer (don't miss out on the pie). I would not reccommend searching for this cache while either one of these events is taking place in the park.
You are looking for a magnetic nano. Please be stealthy as this is a busy area, and replace the cache just as you found it. Happy searching.