To get to the top of the 165 foot tall lighthouse, you must climb 219 stairs. If you are not in good physical condition, you'll likely find yourself stopping for a breather on the way up. If you are in poor physical condition, I suggest you enjoy the view from the ground. If you do make it to the top, though, you will be treated to a fabulous view of the surrounding area.
Construction of the St. Augustine lighthouse began in 1871, making it more than 125 years old. The adjoining house was built in 1876 and, quite unusual in Florida, has a basement. This house is where the lightkeepers and their families lived, up until 1955 when the light was changed to an automated system. Now it is home to the Lighthouse Museum, but the memories of the lightkeepers is well preserved within its walls.
Small as it might be, the Lighthouse Museum is really quite interesting and worth a thorough look over. Exhibits explain the history of the lighthouse, as well as give an education on just what a lighthouse does and how it works. The stories and lives of the lightkeepers are documented here, as well. During the World War Two era, this facility was an active Coast Guard center. The stories surrounding this time period include an intriguing tale of German submarine attacks along the St. Augustine coastline.
The St. Augustine Lighthouse and Museum turned out to be much more interesting than I had expected it to be. It is also an attraction that will appeal to a variety of age groups. I would set aside between one to two hours for touring the museum and climbing the lighthouse. While this is a day time activity, if you go late in the day, the sunset view from the top is hard to beat.