The activities will take place on selected dates throughout July and August in Robin Hood’s Bay, following a successful set of sessions run during the May half-term.
Events include rockpooling and beachcombing.
For sandcastle enthusiasts, there will be a free sandcastle building competition on the beach in the village on Tuesday, July 23.
The National Trust is also providing free Tracker Packs, stocked with guides on rockpooling, bird watching and fossil hunting.
These can be borrowed daily from the Old Coastguard Station in Robin Hood’s Bay, located on the slipway to the beach.
Leanne Allan, senior visitor experience officer on the Yorkshire coast, said: “The sessions we’ve run previously have gone down incredibly well with the families who have attended.
“They’re a fabulous way to introduce children to the marine life on our coastline and our staff will help them better understand what lives here and how to look for them.
“They also show families how to do these activities safely and responsibly, so that they can enjoy them on their own in future.
“We decided to offer the sandcastle building competition as it’s a great seaside tradition and the perfect way to kick off the summer holidays.
“It’s free to enter and there’ll be prizes to be won!
“We hope everyone who comes along to any of our activities has lots of fun and creates some brilliant memories.”
The rockpooling sessions are available on 25 July and on 2, 8 and 31 August.
Beachcombing sessions are available on July 22 and on 3, 7 and 27 August.
Sessions are £3 per child and spaces are limited.
To reserve a space, ring 01723 870138.
Those wishing to participate in the sandcastle building competition must register by 11am at the Old Coastguard Station at The Dock.
The National Trust café and visitor centre at the Old Coastguard Station is open daily from 10am until 5pm.
More information, including session times for the rockpooling and beachcombing sessions, is available at www.nationaltrust.org.uk/yorkshire-coast.
