A major star joins the cast of "Dinosaurs in Their Time" at the Carnegie Museum of Natural History, with the opening of the T. rex section of the revamped dinosaur exhibit. Carnegie Science Center will be home to "Titanic: The Artifact Exhibition" -- a popular traveling exhibit featuring artifacts and re-created sections of the ship. The Children's Museum of Pittsburgh will be one stop for an international festival happening simultaneously there, in France, Italy and Poland on May 31 and June 1.

A summer tradition -- the Gateway Clipper Fleet -- turns 50 this year and is celebrating with new cruises, discounts and renovated boats. The Pittsburgh Zoo & PPG Aquarium celebrates its 110th anniversary with a weekend of special activities on July 12 and 13.

4400 Forbes Ave., Oakland. 412-622-3131.

EXHIBITS: "Arresting Arrangements" -- Photos by Craig Cutler" -- large-scale photographs documenting the remounting of the museum's dinosaur collection last year (through July 27); "Time Machines: Watches From the H.J. Heinz Collection" (through July 6); "Dinosaurs in Their Time: T. rex Returns" -- opening of the final phase of "Dinosaurs in Their Time" exhibit (opens June 15); "In Harmony With Nature II: Photos by Donald M. Robinson" -- works by nature photographer Robinson, on loan from the Southern Alleghenies Museum of Art (May 17-Sept. 14); "Setting Trends: National Jewelry Institute Designer Showcase" (opens July 26); "Born of Fire: The Pottery of Margaret Tafoya" -- exhibit of work by pueblo potter Margaret Tafoya, along with rare early works from Santa Clara Pueblo (Sept. 6-Jan. 4).

One Allegheny Ave., North Side. 412-237-3400.

RANGOS OMNIMAX THEATER: "Dinosaurs Alive!" -- dinosaurs come to the giant IMAX screen (through June 5); "Sea Monsters: A Prehistoric Adventure" -- film using computer-generated animation takes audiences back to the late Cretaceous period (through June 5); "Pulse: A STOMP Odyssey" -- explores the universal language of rhythm through segments filmed in Africa, South America, Spain and the U.S. (through October); "Wild Ocean" -- a look at the massive annual sardine migration in the South African ocean waters, and its impact on the environment and economy (opens June 6); "The Alps" -- the life of mountaineer John Harlin III, who climbed the North Face of the Eiger, the same peak that claimed his father's life (opens June 6); "Mummies: Secrets of the Pharaohs" -- the tombs of the Egyptian pharaohs and Egyptian civilizations (opens Aug. 29).

EXHIBITS: "Titanic: The Artifact Exhibition," traveling exhibit of artifacts recovered from the Titanic, re-creations of the ship's rooms and stories of its passengers and crew (May 24-Sept. 1).

EVENTS: 2008 RoboCup US Open -- Robot soccer players compete (May 24-27); Freezin' Hot Summer Kickoff -- visitors who bring a snowball saved from last winter will be admitted free to weekend of science demonstrations (June 20-22); Super Fourth of July -- rooftop fireworks celebration (July 4 at 6 p.m.; space limited; 412-237-3400 for reservations); Fireworks Science Sleepover -- Point Park's fireworks display, followed by overnight adventure program (July 4, 6:30 p.m.-11 a.m.; registration: 412-237-1637); Robot Block Party -- block party and demonstration of some of the specialized robots developed in the region (July 19-20); "Think Green!" -- eco-friendly technologies, green projects, environmental films and more (Aug. 9-10).

Allegheny Center, North Side. 412-322-5058.

EVENTS: Fi'Art Family Art Festival -- international art festival taking place simultaneously at the Children's Museum and at museums in France, Italy and Poland (May 31-June 1); "Lemurtron" -- musical instruments meet robotic technology (May 31-Sept. 7); Buddy Nutt -- musician performs with ukulele, duck call, musical saw and other instruments (June 14, 2 and 3 p.m.); "Carnival Spectaculaire" -- museum's 25th anniversary celebration with music, acrobats, art, magic and more (June 28; admission 25 cents); Unplugged in the Square -- live music in Allegheny Public Square, using a solar-powered amplification system (Wednesdays in July at noon); Robot 250 Events at the Children's Museum -- BigBot Green Roof Roller Coaster, robotic flower garden and robots built by the museum's YouthAlive program (July 11-27); Carousel Carving -- demonstrations by master carousel carver George Nowack (July 23); Plein Air Painting -- outdoor painting with the Plein-Air Painters of Western Pa. (Aug. 3; rain date Aug. 10); "Kindergarten! ... Here I Come!" -- board a real school bus, make art projects, meet crossing guards and more in this free program for children entering kindergarten (Aug. 9).

Cruises depart from Station Square. 412-355-7980.

DINING CRUISES: Captain's Dinner Dance Cruise (through November); Chicken & Ribs Dinner Cruise (Tuesdays and Thursdays June 3-Aug. 28, Thursdays in September and October); Sunday Dinner Cruise (June 8, 22, July 6, 20, Aug. 3, 17, 31); Hawaiian Dinner Cruise (June 13, July 11, Aug. 8, 29); Polka Dinner Cruises: Stas Golonka & Chicago Masters (July 18); Stephanie, America's Polka Sweetheart (Aug. 15); Captain Jack's Fish Cruise (July 25, Sept. 12); Oldies Dinner Dance Cruises: Johnny Angel & the Halos (June 27); The Vogues (Aug. 1); Golden Triangle Lunch Cruises: Neil Diamond Tribute by Chris Denem (June 20, July 11, Aug. 8); Bo Wagner's Frank & Dean Show (June 27, Aug. 1, Aug. 22); A Tribute to the Magic of Elvis by Don Obusek (July 18, Aug. 15); additional luncheon dates, entertainment TBA (June 6, 13, July 25); Saturday Family Picnic Cruise (June 7, 21, July 5, 19, Aug. 2, 16, 30, Sept. 13, 27); Gospel Lunch Cruise (June 1, July 13, Aug. 10, Sept. 14).

SIGHTSEEING CRUISES: One-Hour Sightseeing Cruise (weekdays June-August; weekends May, September, October); Good Ship Lollipop Cruise (weekends June-August); Sunday Ice Cream Social Cruise (Sundays June 15-Aug. 31); Kids Showtime Cruise -- Pinocchio by Sadecky's Puppets (June 28, July 12, Aug. 23, Sept. 20); Pirates of the Mon by Gemini Theatre Company (June 25, July 9, 23, Aug. 6, 20); Lords of the Mon Cruise -- "Steel, Coal, Coke and the Men who Moved Them" (July 26, Aug. 9, Sept. 6).

EXCURSION CRUISES: Mountaineer Casino Cruises -- Day trip to Mountaineer Casino (June 6, July 11, Aug. 15); cruise and overnight package (June 23, July 28, Aug. 25, Sept. 29, Oct. 27); Old Economy Village and Cruise Tour (July 23).

ENTERTAINMENT CRUISES: Moonlight Dance Cruise (Fridays June 6-Aug. 29, plus Saturday, Aug. 30); 50th Anniversary Celebration Rock Cruises: Corbin Hanner (May 31); Billy Price (July 3); Joe Grushecky (Aug. 22).

HOLIDAY CRUISES: Father's Day Brunch Cruise (June 15); 4th of July Dinner Dance Cruise (July 4); Labor Day Slovene Polka Cruise -- Del Sinchak, The Casuals and The Polka Quads (Sept. 1).

Ligonier. 724-238-3666.

Open May 22-26, May 31-June 1, June 4-Aug. 24, Aug. 30-Sept. 1.

West Mifflin. 412-461-0500.

Park open daily through Aug. 24, Aug. 29-Sept. 1, Sept. 6-7, 13-14

Ridge Avenue and Arch Street, North Side, 412-323-7235.

EVENTS: Anthony Braxton and the Syrinx Ensemble -- jazz ensemble performs music inspired by the sounds of nature in Aviary's free-flight area (May 31, June 1 at 10 a.m.; free with Aviary admission); "Little Peepers" -- children's stories, crafts and live bird encounters (Mondays May 26-Aug. 25 at 10:30 a.m.); "Two-fur-Tuesdays" -- two admissions for price of one (Tuesdays May 27-Aug. 26); Early Bird Special -- early-morning program with live bird presentations, bird-feeding and continental breakfast (June 7 at 8:30 a.m.; reservations required, 412-323-7235, ext. 249.); "Dino-soars! Summer Camp" -- five-day camp with visits to National Aviary, Pittsburgh Zoo & PPG Aquarium, Carnegie Museum of Natural History's "Dinosaurs in Their Time" exhibit, a fossil dig and trip to Laurel Caverns (July 7-11, ages 6-8; July 14-18, ages 9-11; July 21-25, ages 12-14; scholarships available; information and reservations: 412-323-7235, ext. 209).

Schenley Park. 412-622-6914.

EXHIBITS: "Chocolate!" -- chocolate-themed plants, activities and displays (through Nov. 9); Butterfly Forest -- several species of butterflies will hatch and fly around the Conservatory's Stove Room (through Oct. 11).

One Hill Road, Highland Park. 412-665-3639.

EVENTS: "Wild About Cats and Dogs" -- meet the zoo's lions, tigers, snow leopards and African wild dogs, along with cats and dogs awaiting adoption at local animal shelters (May 24); "The 2008 Save Our Wild Salmon National Road Show" -- the Save Our Wild Salmon Coalition, which is touring the country to raise awareness about the plight of wild salmon, makes a stop at the zoo (May 26-27); Dragon Renaissance Festival -- learn about the zoo's Komodo dragon and leafy and weedy sea dragons, along with knight matches and renaissance characters (June 14-15); Idearc Media Father's Day Celebration -- free admission for dads accompanied by their children (June 15); 110th Anniversary Celebration (July 12-13); Idearc Media Gorilla Day -- meet the gorilla keepers, listen to African drumming and storytelling, plus other activities (July 20); Summer Safari -- over-21 party (July 25; tickets on sale June 16); Children's Hospital Baby Day -- learn about the zoo's baby elephants, child safety and nutrition tips (Aug. 2); PPG Behind-the-Scenes Evening Tours (Aug. 2); PPG Festival of Water -- scuba diving and other sports, plus water safety (Aug. 7-10); UPMC Health Plan Summer Kids' Zoofari (Aug. 16-29).

1212 Smallman St., Strip District. 412-454-6000.

EXHIBITS: "Pittsburgh Recast" -- documenting the city's history by Pittsburgh Society of Illustrators (through Sept. 7); "The Darkest Month" -- commemorating the 100th anniversary of the Monongah and Darr mine disasters of December 1907 (through Sept. 21).

EVENTS: "Family Saturdays at the History Center: Can You Dig It?" -- family activities related to coal mining and "The Darkest Month" exhibit (May 17, 10 a.m.-noon and 12:30-2:30 p.m.); "Sports, Oh the Fun of It!" -- program and activities following tour of the History Center's Western Pennsylvania Sports Museum (June 14, 10 a.m.-noon and 12:30-2:30 p.m.); Federated Investors Parade of Champions -- fan festival with representatives from the Pirates, Penguins and Steelers, plus championship trophies, interactive sports activities and more (June 20-22; Information: www.ticketmaster.com or 412-323-1919); Live and Learn Weekends -- highlight issues faced in Pennsylvania during the Underground Railroad and Civil War era; reception, discussions and guided tour of the LeMoyne House (at Washington & Jefferson College June 20-21 and Blairsville Underground Railroad Aug. 15-16; reservations/information: 412-454-6411); "Homes of Coal" -- learn about life in a Western Pennsylvania coal town, with music food and activities (Aug. 23).

1000 Sandcastle Drive, West Homestead. 412-462-6666.

Open daily from June 7-Aug. 24, Aug. 30-Sept. 1

Next to Carnegie Library, Oakland.

EVENTS: Azucar -- Latin dance (May 22, June 26, July 24 at 7 p.m.); Carnegie Library of Pittsburgh 11th Stack Read Aloud Series -- lunchtime readings for adults, read by Carnegie Library staff (May 23, June 27, July 25, Aug. 29 at noon); PNC Carousel Tea at Schenley Plaza -- children's tea party, with live performances and carousel rides (May 31 11 a.m.-2 p.m.; adults/$50, children 2 and older/$25); Sundae Flea Markets at Schenley Plaza -- vendors, music, farmer's market (June 1, 15 noon-5 p.m.); Kids Day -- free carousel rides, caricature artists, puppet shows and more (July 13, Aug. 17 at 2 p.m.); Klezmer by Ortner-Roberts (July 27 at 6 p.m.); Riverhounds Soccer Clinic & Autographs (Aug. 24 at 1 p.m.); Pittsburgh Filmmakers Movie Nights at Schenley Plaza -- Family movies including "The Wizard of Oz," "Duck Soup," "Grease" and "Angels in the Outfield" (Aug. 2, 9, 16, 23); Yoga @ the Plaza (Mondays at noon May 12-July 28).