On October 25, 2006, Sandcastles, A Lake Michigan Children’s Museum, was established with a board of 6 members who applied for non-profit status. In March, 2007, the first exhibit, Help Us Build the Museum, went on display at the Family AfFair. In June, Sandcastles opened for its first summer on South James Street. We held a Summer Science Camp and sponsored activities at Friday Night Lives, the Mason County Fair, and Oktoberfest.

In June, 2008, Sandcastles opened for its second summer with a new theme, Michigan Wildlife, featuring a giant interactive treehouse with a puppet theater, a Pere Marquette River water table, an interactive apple tree, 20 Discovery Tubs, and an infant section. Special programs were offered on Thrilling Thursdays, and Wildlife Rescue, a new traveling exhibit, was featured at Friday Night Lives. Attendance averaged 1,500 each month. 

In 2009 Sandcastles moved to a much larger, more visible location on West Ludington Avenue. Official attendance for the 2009 summer season was 12,645. Munchkin Mondays were added for preschool programming, and Thrilling Thursdays focused on school-aged children. The new theme was Our Neighborhood, and new exhibits included a grocery store, ice cream shop, post office, sailboat, and bubble table. Due to many requests, the museum was open on Fridays and Saturdays from 9:30 a.m. to 1:00 p.m. through December 19.

The 2010 season brought many changes. Our theme exhibit was Grandpa’s Farm, complete with a milkable cow, a vegetable garden, a conveyer belt and silo, a large farm truck, and tractors. Another new exhibit was the Badger PlayShip, donated by Don and Bobbie Clingan. Added to Our Neighborhood was a bank built by Home Depot employees. New easels for the Art Center were donated by the Pentwater Toy Box. There was a full schedule of Munchkin Monday and Thrilling Thursday programming, and we participated in Friday Night Live with outdoor exhibits. Sandcastles was open on Friday and Saturday mornings through early afternoons with special programs for preschoolers (Playgroup Fridays) and school-age children (Super Saturdays).In 2010 we had 4 part-time employees – a manager and 3 staff members. Attendance for 2010 was over 15,000.

In November 2010, the Sandcastles Board purchased the former Elks building, a lovely historical site in a prime location in downtown Ludington. From closing through spring of 2011, over 125 wonderful, hard-working volunteers worked to renovate and update the building for an early May opening. The Board also entered into a capital campaign to raise $300,000 to complete the purchase, pay for materials and necessary paid labor for renovations, and update building systems.

The 2011 season was an outstanding success. Children and families raved about our building. We had two new exhibits - an interactive, electronic SMART Table and a Vortex Wishing Well. We debuted our fantastic nutcracker collection, donated by former Ludington resident and teacher Doug Wilson. We joined the New Year's Eve festivities with a party for families at the museum. Our attendance for 2011 was over 20,000.

In 2012 we added a bouldering wall (horizontal climbing wall), a saltwater fish tank, and a construction zone. We opened for a week during local spring break and stayed open for weekend hours after that. Many classes from area schools held their spring field trips at Sandcastles. In August, Kristin Korendyke left her position as Board President to become our Executive Director. Attendance again topped 20,000.

As 2013 began, we were busy building, installing, and decorating our major new exhibit, Take Flight!  In addition to the real airplane, control tower, baggage loader, hangar, and customs, we added two destinations:  Egypt and the Amazon.  A large dollhouse was another new exhibit, and we added to our saltwater tank. We opened for local spring break and were then open weekend hours until the summer season began on June 7. We stayed open through Christmas break and again celebrated New Year's Eve with a special balloon drop.  Attendance again topped 20,000.

In 2014, we opened for weekends in February and March and for two weeks for spring break.  We continued weekend hours until we opened for the summer in early June. Thanks to a grant from the Paine Foundation, every Head Start and Great Start child and a parent were eligible for a free visit in 2014 or 2015. We set a new one-day attendance record with 818 and a new annual attendance record with over 23,000. 

During the winter of 2015, we renovated the 2nd floor (previously used for storage) and stairway and added a roof deck and fire escape.  Grants from the Paine Foundation, Great Lakes Energy People Fund, and the Community Foundations for Mason and Oceana Counties gave us a great start, and an anonymous matching grant challenge for $50,000 and numerous individual gifts enabled us to finish the work debt-free.  Our major exhibits upstairs include the Sandcastles Ludrock music stage (with instruments and real-time video of “performances”) and Grandpa’s Farm, brought out of storage. We frequently use the music stage for special performances and events even during our off season. Our Musical Playground was installed on the roof deck, which was also used for workshops.  Attendance was again over 23,000. 

In 2016, we replaced flooring on the upper tier of the main floor.  In our lower level party room, we updated lighting and ceiling tiles and installed donated cabinets and countertop. With CFMC financial support, we fixed the roof and the cupola at the front of the building. In partnership with the city of Ludington, we received a block grant from the state of Michigan.  During the summer, all of the brick and stone on the exterior of the building was repaired and tuckpointed with money from the grant and our matching funds.  There were 60 middle school Discovery Guide assisting staff and adult volunteers. Over 300 people attended our Balloon Drop and Stomp on New Year's Eve.  

2017 was a very busy year.  With support from Spectrum Health Ludington, we installed a beautiful newborn nursery exhibit with many realistic stations. We added Grandpa's Little Farm, purchased with a grant from the GLE People Fund, for miniature play. In May, we held a grand 10th anniversary celebration. A grant from the CFMC provided a new heating/cooling system for our main office area, which we completely remodeled in October. 

In 2018, we added a new pirate-themed Infant/Toddler Discovery Zone. We also renovated our office and main floor storage areas. Grants from the CFMC helped with both projects. Free workshops included Chemistry for Kids and Robotic LEGOs, supported by OXYChem, and Digital Photography, Stop Motion Animation, and Chroma Key Video Production, supported by Michigan Council for Arts and Cultural Affairs. Discovery Guides presented a puppet show each Tuesday morning during the summer.

Another major renovation was completed in 2019. The office on the top floor was not only renovated, but we tore out the wall between it and the open area at the top of the stairs to create a large new exhibit space. With CFMC support, we installed an accessible restroom and refinished the original maple floor. Hardman Construction partnered with us to install Building Foundations, a multi-station heavy construction exhibit. We again held many free workshops. The MCACA granted support for several art and technology workshops, including a new addition, Photoshop. OXYChem supported our Chemistry explorations. A welcome new addition to our preschool programming, a SoftZone Tunnel Maze Climber, was purchased with grant funds from Great Lakes Energy People Fund. We set a new record for memberships.

We currently have a 9 member volunteer board and many dedicated volunteers who work at the museum, build exhibits, and assist with record-keeping, maintenance of exhibits, and programming. Each year we apply for grants that match our current plans and hold fund-raisers to help us realize our long-term goals and capital projects.  We are building an endowment within the Community Foundation for Mason County.