Boulders resembling pink elephants, castle ruins, crystal-clear waters and incredible underground spaces—visitors can explore all these and more at the 90-plus state parks across Missouri. With so many to choose from, where do you start? Here's a roundup of 10 of the state's best parks, perfect for any Show-Me State itinerary.

The crumbling remains of a business tycoon's dream home now provide the backdrop for one of Missouri's most beautiful state parks. In 1904, Robert McClure Snyder purchased Ha Ha Tonka Lake and Spring and began to build a grand limestone castle. Snyder died in a car accident before the project was complete. His sons finished the enormous home, which later became a hotel and resort before it was leveled by fire in the 1940s. The state eventually bought the land and turned it into Ha Ha Tonka State Park. Visitors can wander through the mansion ruins, check out the on-site cave, rent kayaks, or hike into the bluffs for commanding views of the Lake of the Ozarks. 

Related: Top Things to Do at Lake of the Ozarks

Scrambling up the giant boulders at Elephant Rocks State Park in southeast Missouri is a memorable rite of childhood for many Missourians.  Formed 1.5 billion years ago, the park's enormous stones are prized for their pink hue. The granite used to be quarried onsite and shipped via railroad to St. Louis (where it was used in City Hall) and beyond. A mile-long Braille Trail, accessible for people with vision limitations, takes visitors through most of the huge rocks; an extension leads to the ruins of an old railroad house. Climb up far enough to spy eerie etchings from the past; miners who once worked the site carved their names and comments deep into the stone.

Related: Find Outdoor Rec and History in Southeast Missouri

When visitors experience all the Ozarks recreation options Echo Bluff State Park in Eminence offers, few are surprised to learn that the park was once a summer camp. You can float, fish, snorkel, swim and kayak here, as well as take advantage of mountain biking and hiking trails.  The accommodations are top-notch, with cabins plus a new full-service lodge with indoor and outdoor dining rooms. Don't miss sunset over the park's namesake bluff. The dolomite cliff rises hundreds of feet above Sinking Creek and looks majestic as the sun goes down.  

Who needs a fancy water park when you've got Johnson's Shut-Ins? The standouts at this state park are the natural waterslides created by the Black River rushing through large granite boulders. Shoot through rushing rapids or soak and lounge in calmer pools.. A boardwalk allows visitors a scenic look over the rapids. Word to the wise: if you go to Johnson's Shut-Ins State Park, make sure you've got heavy-duty water shoes with decent tread—the rocks here are slick!

The 240-mile long Katy Trail State Park runs along what used to be tracks used by the Missouri-Kansas-Texas Railroad. Today, this pancake-flat crushed stone path is the longest developed rail-trail in the country. Stretching across a good portion of the state, the Katy winds its way near the Missouri River, through bluffs and rolling farm fields. It has 26 trailheads, many in small, scenic towns. It's not uncommon for biking enthusiasts to plan a multi-day trip, traversing the trail from start to finish. Pedestrians and horseback riders are also welcome on the Katy.

One of the state's most popular fishing holes, Bennett Spring State Park in Lebanon teems with trout, and a fair bit of history, too. Back in the 1800s, settlers realized Bennett Spring with its rushing rapids was the perfect place to build grist mills. The surrounding valley provided farmers a scenic place to camp while waiting for their grain to be ground. Each day, the spring releases 100 million gallons of water, providing a dramatic backdrop for anglers. More draws to Bennett Spring: hiking trails and a nature center.

The area that is now Castlewood State Park had a resort heyday in the early 1900s. Clubhouses, taverns, hotels and dance halls attracted thousands of visitors from St. Louis each summer. Only a few foundations and a concrete staircase remain from that party past, but the park now appeals for its excellent hiking and mountain biking trails that reach up into the bluffs along the Meramec River. 

Located at the headwaters of the spring-fed Current River, Montauk State Park contains a fish hatchery, and thanks to regular stocking, is popular with anglers looking to hook trout. If fishing's not your thing, the park also contains three buildings listed on the National Register of Historic Places, including an 1896 grist mill that's open for tours. Montauk's onsite lodge even features a restaurant that will clean, cook and serve your day's catch.

Not far from the state's flagship university, Rock Bridge Memorial State Park in Columbia gives visitors an off-campus nature refuge, much of it underground. As its name suggests, the park's trails wind past striking geologic formations, with a rock bridge and numerous sinkholes. While currently closed to the public to protect its bat residents, Devil's Icebox with its chilly temperatures and underground stream is worth a peek from the outside. Visitors can also have a mini spelunking adventure in Connor's Cave, but be sure to wear sturdy shoes and bring a flashlight.

Related: Best Things to Do in Columbia, Missouri

Another spring-fed stunner, Roaring River State Park lies in a deep, narrow valley surrounded by southwest Ozark hills. Roaring River, which emerges from a deep underground cave system, is stocked daily with trout, making it popular with fishing enthusiasts. Hikers enjoy the park's seven trails; families also love the Ozark Chinquapin Nature Center, with interpretive displays about the park's natural history.

Two of the state's largest resort areas—Lake of the Ozarks and Table Rock Lake—also feature terrific state parks. When you've had your share of fun on the Bagnell Dam Strip and need a nature recharge, Lake of the Ozarks State Park has you covered. Its trails meander through woodlands, glades and bluffs; there's also beach access. And if you're heading to Silver Dollar City, Table Rock State Park near Branson is your best state park bet. The marina offers water rentals of all sorts, from ski boats to paddleboards.