This letter box is located on a wheelchair accessible trail (but you'll need to leave the trail to get the nut).
As with my other letterboxing hybrid the GPS coordinates provided are correct - but you can follow the traditional letterboxing clues:
Park at the Spanish River Library to access the trail head. After you park go across the bridge and follow the sign to the Pondhawk Natural Area entrance. At the kiosk you can grab a trail map.
When you cross the wooden walkway you will come to the paved trail (green trail on the trail map) - you can either go straight (north) or left (west). if you choose to go west you can go directly to the cache. But if you go straight you can read each point on your trail map. This is optional of course, but very enjoyable and educational.
Follow the path all the way to the observation deck (just after number 8 on the trail). Enjoy the view of the restored wetland.
Once you reach the platform look to the south of the platform and you'll see a small group of Dwarf Palmetto (Sabal Minor). The nut you seek is between the trees.