Schools in New Castle, New Hampshire, the US. Schools locations in New Castle, New Hampshire. Find the nearest schools locations, near you. All types of business services Real estate School Travel All schools in New Castle M H Trefethen School School +1 603-436-5416 142 Cranfield Street, New Castle, New Hampshire 03854 Write a review Phone Directions UNH coastal marine lab School 29 Wentworth Road, New Castle, New Hampshire 03870 Write a review Phone Directions