Families looking for late-summer fun can enjoy several activities within a short drive of Bangor.

Fort Knox State Park, a 19th-century fort located on a point of land in the Penobscot River in Prospect, provides a scenic picnic spot for families to enjoy, while learning first hand of local history. The massive fortification was built during a border dispute with Great Britain to protect coastal and riverfront towns in case of war, which never came.

The granite-and-brick fort was never used in battle, but was the site of training exercises in the late 19th century. Outside, picnic tables, charcoal grills and restrooms are available. Trash must be carried out of the park and dogs are allowed, if kept on a four-foot leash and if owners clean up after them.

Both guided tours and individual exploration of the fort are offered. Visitors should plan to spend about an hour touring the inside. Caution is recommended in the dark interior of the narrow fort passageways, but visitors of all ages can appreciate and enjoy the historic site.

“We recommend that you bring a flashlight, because there are dark underground alleyways. We advise no running in the fort since the granite floor is damp and slippery,” said Sylke Nesensohn, who works as a tour guide at Fort Knox.

Guided tours are offered daily at 11:30 a.m. and 1 p.m. weekdays, with an additional weekend tour at 2:30 p.m. Hours through Sept. 15 are 9 a.m. to sunset. Admission at the state park is free for those age 4 and under or age 65 and over. Ages 5-12 pay 50 cents each; ages 12-64 pay $1.50 apiece. The guided tour is included in the price of admission. For more information, call 469-7719.

Further inland just off Rte. 15 in East Orland is Craig Brook National Fish Hatchery, the oldest salmon hatchery in the United States. Salmon pools used to hold the 1-year-old parr and 2-year-old smolt have been reconditioned and are being restocked. Inside the visitor’s center, older children and teens may find the information on salmon more interesting than will smaller children.

However, visitors of all ages can enjoy picnicking and swimming at Alamoosook Lake, which is adjacent the hatchery. Boat launching also is available there. There is no charge for the fish hatchery or Alamoosook Lake.

“It’s a nice family area,” said Tom King, assistant hatchery manager for the Green Lake/Craig Brook Complex. For more information, call 469-7719.

On Route 3 in Trenton, the Acadia Zoological Park features a 100-acre game preserve and zoo simulating a variety of natural habitats, including woodlands, streams, shady trees and open pastures.

The preserve is home to more than 150 native and exotic animals and birds in Maine’s largest animal-petting area.

Those who want to pack a picnic will find tables available, and for a fee, pony rides for small children. The park is open until Columbus Day; the hours are 9:30 a.m. to 6 p.m. Admission is charged. For more information, call 667-3244.

The Natural History Museum at the College of the Atlantic in Bar Harbor houses a variety of taxidermic exhibits depicting birds and animals in their natural setting, such as an owl ready to grab a skunk or a coyote peering at a chipmunk.

Daily participatory programs include assembling a 20-foot whale skeleton; examining a bird’s wing, and handling an array of skins to be studied.

The “Discovery Corner” is a favorite of youngsters and includes a “please, touch” area, including a tank of marine creatures. There are shelves of field guides, items to identify, books to read and crayons and paper for coloring. The museum is open from 9 a.m. to 5 p.m daily until Labor Day. For more information, call 288-5015.

In Southwest Harbor, the Mount Desert Oceanarium is a popular spot for all ages. A full-sized lobster boat with a working marine-radio receiver sits beside the oceanarium just for make-believe lobster fishing.

Inside the oceanarium, all but a few of the exhibits are designed for touching.

Ocean-going equipment at the oceanarium includes a sea chest with a fisherman’s foul-weather gear, the mock-wheelhouse with steering and electronic nagivational aids, the great barrel challenge for identifying objects by touch only, various safe-at-sea gear, and a scale for checking your weight under water.

More than 20 saltwater tanks contain Gulf of Maine creatures to be explored by watching or by using magnifying glasses or a microscope. In one tank, creatures can be explored by touching them.

The oceanarium is located off Route 102 on the Clark Point Road and is open from 9 a.m. to 5 p.m. Monday through Saturday until mid-October. Admission is charged. For more information, call 244-7330.