Marie and Douglas Pyle of Lewisville, Texas, stroll along the 950-foot breakwater that leads to Spring Point Ledge Lighthouse in South Portland during Maine Open Lighthouse Day on Saturday. Visitors say lighthouses are must-see icons of Maine.

Crowds gather above and below Bug Light on Saturday during Maine Open Lighthouse Day. Ben McCanna/Staff Photographer

Siblings Avery, left, and Case Lappin, of South Portland, scan the waters for marine life while waiting to enter Bug Light on Saturday during Maine Open Lighthouse Day. Ben McCanna/Staff Photographer

It's a dizzying view from atop Portland Head Light. Ben McCanna/Staff Photographer

U.S. Coast Guard fireman Justin Busch leads a tour group up the spiral staircase within Portland Head Light on Saturday. Ben McCanna/Staff Photographer

Dave Wetherbee of Bath takes a photo of the very thing that appears on his race jersey -- Portland Head Light. Wetherbee stopped to take a photo after riding in the 62-mile Maine Lighthouse Ride on Saturday. The race course passed eight lighthouses, which coincided with Maine Open Lighthouse Day. Ben McCanna/Staff Photographer

Crowds gather above Bug Light on Saturday during Maine Open Lighthouse Day. Ben McCanna/Staff Photographer

A crowd gathers above Portland Head Light on Saturday during Maine Open Lighthouse Day. Ben McCanna/Staff Photographer

Holly Conroy, of Leominister, Massachusetts, rings the bell at Spring Point Light. Ben McCanna/Staff Photographer