Florida State Road 666


State Road 666 is a short state road in Pinellas County. Locally known as Tom Stuart Causeway, the route crosses Boca Ceiga Bay from Seminole to Madeira Beach. The bridge crossing Boca Ceiga Bay is a Bascule Drawbridge with 11 spans. The route ends with an interchange with U.S. Route 19 Alternate in Bay Pines. The southwestern terminus of the route is at State Road 699 in Madeira Beach, in front of the Ocean Sands hotel.

Major intersections