The Curonian Spit is a UNESCO World Heritage Site. This national park is known for its ‘singing’ sands and ‘dancing’ trees. Sean Thomas travels to the Great Dune Ridge, the Spit’s main ridge, formed from sand carried from the coastline by wind and waves. When the grains rub together, they produce a rustling or squeaking sound — that is why the sand is said to ‘sing’. The Spit is also home to a ‘dancing’ pine forest. Planted in 1961, many of its trees already have oddly twisted trunks.