THE SPIRAL staircase isn't supposed to be the most exciting part of the Drum Point Lighthouse self-guided tour. And to most people, it's not. But to my sons, ages 2 and 4, climbing up and around, up and around was akin to a carousel ride. For the rest of us, the excitement started when we stopped at the top and looked down.

Below us was the boat-building exhibit at the Calvert Marine Museum in Solomons, Md., made tiny by the height. On the other side we stared at open water and imagined the isolated lives of the first light keepers.

Unlike the original occupants of the 1883 lighthouse, which is part of the museum, we did not need to take a boat over and swing ourselves onto a ladder. We had walked along a solid dock and then up into the house and the business of the light keepers. Originally, the lighthouse was at Drum Point, where the Patuxent River flows into the Chesapeake Bay. Decommissioned in 1962, it was moved to its present location in 1975 and restored to its early 20th-century appearance. Since then, it has been connected to land.

The living quarters -- clean, white and beautiful in their simplicity -- are, of course, round. My sons ran -- make that walked quickly -- from the living room to the bedroom to the kitchen and back to the living room. They asked "What's that?" about a chamber pot. A small trunk, used to send and receive library books, also caught their attention. The closet in the kitchen, which one of them opened, was not a pantry as we expected but an impressive system of weights and counterweights. A sign explained: Moving cargo and lights into a tall structure required a great deal of lifting power.

This lighthouse isn't used anymore, and there aren't any manned lighthouses on the Bay, but there is still a mystique to living in or next to the big light. My kids and I wanted to know how the keepers got breaks from work. Did they feel as isolated as it looked? And what about all those stairs? This weekend we can find out. The museum is hosting a Winter Lights Weekend Saturday and Sunday, with exhibits on East Coast lighthouses and actors playing keepers. Visitors can ask these questions and others.

The Calvert Marine Museum itself is a great destination for both old and young ocean enthusiasts. Due to my kids' ages, we skimmed the exhibits about life along the Chesapeake, but we stood mesmerized by the sea otter twisting elegantly in her tank and gaped at the gigantic fish skeletons from earlier geological times.

Then there was the discovery room. It's a kid-pleaser with dress-up sailor clothes; books; puppets of sea creatures; magnetic fishing poles and metal fish; and sharks' teeth.

A large box holds the teeth plus a whole lot of sand. Children sift through the sand and find a treasure, or, if you're only 2 like Evan, you just sift. Scott, 4, found a tooth he was allowed to take home; he took it to the museum's resident paleontologist, who said it came from a snaggletooth shark of the Miocene epoch (23.8 million to 5.3 million years ago).

When we got home, the shark's tooth went up on Scott's wall, a great souvenir of a well-spent afternoon.

CALVERT MARINE MUSEUM -- Solomons Island Road South, Solomons, Md. From the Beltway, take Route 4 south to Calvert County. When you reach Solomons, turn left onto Solomons Island Road. 410-326-2042. www.calvertmarinemuseum.com. Open 10 to 5 daily except Dec. 25, Jan. 1 and Thanksgiving Day. Drum Point Lighthouse is open year-round, weather permitting. The discovery room is periodically reserved for school groups. $5, $4 for seniors, $2 for children 5 through 12 (under 5 free).

A box full of sand in the discovery room at Calvert Marine Museum holds surprises for enterprising children to find.