It's been nearly 225 years since Congress called for lighthouses "beacons, buoys and public piers" to be built for the safety of the public and seafarers. You can celebrate that occasion, which fell back on August 7, 1789, by visiting one of the many lighthouses across the National Park System in the weeks to come.

Among the more unusual lighthouses out there is the Sullivan's Island Lighthouse, the last major lighthouse built in the United States (it was commissioned in June 1962).

Rising above Fort Sumter National Monument, the light is not round, but triangular, more like an air traffic control tower than a traditional lighthouse.

On August 7 monument officials are inviting the public to "explore the grounds of the U.S. Coast Guard Historic District on Sullivan's Island. While the grounds, quarters cupola, and boat house will be open to the public from 1 p.m. to 5 p.m., due to safety concerns only the base of the lighthouse will be open to the public.

Understandably, not everyone lives within a short drive of Sullivan's Island.

But there are many more lighthouses across the National Park System, some that you can still climb to the top in, others than you can simply admire from a distance. Here's a look at some of those out there:

Acadia National Park

Perhaps the most-photographed lighthouse in the northeast is the Bass Harbor Light that stands on the southern tip of the national park, warning ships and boats of the shoals at the head of Bass Harbor.

Apostle Islands National Lakeshore

There are six historic light stations dating from 1856 (Michigan Island) to 1891 (Devils Island) at the lakeshore. Lighthouse historian Ross Holland judges this to be the largest and best collection of historic light houses in the United States. Eight light towers ranging in age from 88 to 155 years are included among the park's 181 other historic structures, and there is also a light tower ruin.

Raspberry Light is one of the lakeshore's focal points for interpreting the cultural history of the islands. A couple of years ago the light was restored, gaining a new roof, foundation repairs, and interior work. Today half of the station appears much as it did in the early 1920s when Lee Benton was its keeper, while half provides housing for lakeshore personnel.

Cape Cod National Seashore

This national seashore can count more than 20 lighthouses on Cape Cod during the past 200 years on the cape. Today the main ones are:

* Cape Cod Light, located near Truro. Tours are offered to the lantern room through the summer.

* Nauset Light, which is near North Eastham. Tours have been offered on Sundays during the summer months and into fall.

* Race Point Light is near the tip of Cape Cod.

* The Three Sisters, which are three 15-foot masonry towers that long ago were decommissioned but are still fun to visit.

Cape Hatteras National Seashore

This national seashore has three lighthouses: Bodie Light near Nags Head, Cape Hatteras Light at Buxton, and Ocracoke Light at Ocracoke, though only one, the Cape Hatteras Light, currently is open to the public. It's a great climb to the top, where you'll find sweeping views of the Outer Banks.

Cape Lookout National Seashore

The Cape Lookout Lighthouse is open to the public throughout the summer. The easiest way to reach it is to take a passenger ferry from Harker's Island to the Park Service dock below the light.

Channel Islands National Park

Anacapa Light. It's said there are escorted tours available. You can read up on the light's history at this Park Service page.

Fire Island National Seashore

Fire Island Light, where the Fire Island Lighthouse Preservation Society has offered tours in the summer months.

Gateway National Recreation Area

Sandy Hook Light, where the New Jersey Lighthouse Society has offered tours to the top on weekends in summer.

Golden Gate National Recreation Area

Alcatraz Island Light dates to 1854. It has an interesting daymark: the tower is uncolored reinforced concrete, while the light at the top is black.

Isle Royale National Park

This national park counts four lighthouses: Isle Royale Light, Rock Harbor Light, Passage Island Light, and Rock of Ages Light.

Kalaupapa National Historical Park

The Molokai Light is found at this historical park on Molokai. Brought on line in 1909, the 138-foot-tall lighthouse is the tallest U.S. lighthouse along the Pacific Ocean, according to the Park Service.

Pictured Rocks National Lakeshore

The Au Sable Light, which has a history that dates to 1874, usually offers guided tours in the summer months.

Point Reyes National Seashore

Point Reyes Light, a 35-foot tall structure, dates to 1870 to help ships navigate the second-foggiest place along the North American continent (according to the NPS). "The Point Reyes Headlands, which jut 10 miles out to sea, pose a threat to each ship entering or leaving San Francisco Bay," the agency notes in discussing the light's history.

Sleeping Bear Dunes National Lakeshore

You have to leave the mainland to reach South Manitou Island Light, but it's open for tours daily in summer. Long ago there was a lighthouse on North Manitou Island, but it closed down in 1927 and was replaced by a lightship.