Sail the seas with Fido at Mystic Seaport Museum, the largest maritime museum in the U.S. Located in Mystic, CT, the museum covers 19 acres and features more than 500 historic watercraft, as well as a recreated New England coastal village and a working shipyard. Check out the Charles W. Morgan, an 1844 whaleship and America’s oldest remaining commercial ship. Leashed pets are welcome on the museum grounds but are not allowed in any buildings or museum vessels. After exploring Mystic Seaport Museum on foot, leave it in your wake with a boat ride. Borrow one of the museum’s pet-friendly rowboats, sailboats or pedal boats and get out on the Mystic River with your tail-wagging skipper.

For a truly out-of-this-world experience, bring Fido to the dog-friendly International UFO Museum & Research Center in Roswell, NM. Roswell was the site of an alleged UFO crash known as the infamous 1947 “Roswell Incident,” and the museum is committed to chronicling that and other UFO events across the globe. Bring your leashed, well-behaved dog to the museum and explore decades of supernatural history, research and science. Before you leave, stop by the pet-friendly gift shop to buy some extraterrestrial memorabilia to take home.

Four-legged aviators are welcome at the Pima Air & Space Museum in Tucson, which offers an unparalleled aeronautical experience. The museum has 100,000 square feet of indoor display space filled with an array of 350 aircraft and spacecraft for you and Fido to explore. It’s one of the largest non-government-funded aviation museums in the world, with aircraft from all over the world and a special building dedicated to planes from World War II. Leashed pups are permitted on the self-guided walking tour of aviation history, but not on the tram.

The History of Diving Museum in Islamorada invites you and your leashed canine buddy to explore the ocean blue. The museum features one of the world’s largest collections of diving equipment, including helmets, hand-operated air pumps, armored suits and lights from more than 30 countries around the world. You and Fido can learn about the history of military, commercial and recreational diving, and how diving has contributed to marine science, underwater photography and treasure hunting. When you’re done viewing the displays, stop at the gift shop to purchase a unique diving-related souvenir.

Choo choo with your pooch at the Seashore Trolley Museum in Kennebunkport, one of the oldest and largest transit museums in the world. Its permanent collection showcases the evolution and history of public transportation around the world, including omnibuses, electric streetcars, buses, light rail vehicles and rapid transit cars. Dogs are always welcome to explore the exhibits and attend special events. The museum is open from May to October.

Is your dog the king of the household? Then he'll feel right at home at Miramont Castle Museum in Manitou Springs, CO. At this 19th century Victorian castle preserved by the Manitou Springs Historical Society, you and your pup can visit 30 beautiful rooms with authentic Victorian furnishings. Leashed dogs and cats are allowed to roam the castle and might even meet Chip the Castle Dog, Miramont's 15-year-old Golden Retriever.

Two- and four-legged history buffs will love taking a trip back in time at the pet-friendly Spanish Military Hospital Museum. The museum's fully guided tours take you back to the Colonial Spanish days of medicine. Your adventure into the past begins as their skilled surgeons perform virtual surgery. Watch as the apothecary creates medicines, and discover how colonial herbs were the origins of some of the most popular medicines today. Dogs and cats are always welcome, and the museum receives pet guests almost daily.

Life is a highway, and you and Fido will ride it all night long at the Gilmore Car Museum in Hickory Corners, MI. The dog-friendly museum chronicles the history of the automobile with a collection of more than 500 vehicles, including an 1899 Locomobile Steam Car. Along with its extensive car collection, the museum features a train depot, a Disney movie set, a 1930s gas station and a display of more than 1,500 automotive mascots and name badges. Leashed dogs are welcome on the museum grounds, but only small pups that can be carried are allowed in the buildings.