David Marteen was a Dutch privateer (A privateer was a private person or ship that engaged in maritime warfare under a commission of war) based in Tortuga during the mid-17th century. His ship conducted raids against Spanish strongholds in Mexico and Nicaragua during 1663 until 1665. In one of these raids, he led his men 50 miles overland and successfully looted a series of villages.
He looked for a safe place to bury his treasure and for some reason known only to him he decided to sail about a thousand miles north to Connecticut and then sailed up the Connecticut River and came ashore in an area around Windsor called "Big Hill". From there he eventually moved west along the Farmington River to the Salmon Brook River where he and his crew buried their silver, gold and jewelry.
Is there any truth to the story? Well the Dutch, who essentially settled large parts of Connecticut, were still a force in area in 1650 and Marteen may have seen the Nutmeg state as a new beginning. However Marteen wasn’t a pirate in the modern sense, wasn’t wanted by anyone except the Spanish and had no reason at all to bury his treasure.