Fort Wool (originally named Fort Calhoun) was the companion to Fort Monroe in protecting Hampton Roads from seafaring threats. This site was once the dumping place for ships’ ballast. Originally conceived in 1817, Fort Calhoun was built on a 15 acre (61,000 m²) artificial island southeast of Old Point Comfort in Hampton, Virginia. Construction and repairs continued for decades, because the foundation was unstable. The first level of casemates was finished in 1830. Construction continued through the 1830s, when Andrew Jackson came to escape from the heat of Washington, D.C. As a young second lieutenant and engineer in the U.S. Army, Robert E. Lee was stationed there from 1831 to 1834. Lee was an assistant to Captain Andrew Talcott and played a major role in the final construction of both the fort on the island in 1834, and its larger opposite on the mainland, Fort Monroe. The first fort was originally called Ripraps (a name still often used; see Rip Raps for a possible history behind the name), and later Fort Calhoun. The Fort played a crucial role for the Union forces during the American Civil War. In addition to aiding in controlling entrance to the harbor of Hampton Roads, prisoners were confined in the fort. After the Civil War it was named Fort Wool for the Union Major General John Ellis Wool, who captured Norfolk in the early part of the war. The Fort was modernized in the early 20th century, and served as the part of the harbor's defense during World War I and World War II. During World War I submarine nets were stretched across the harbor from this point. In the 1950s, the southern man-made island of the Hampton Roads Bridge-Tunnel was constructed next to Fort Wool, and used as the southernmost anchor for the tunnels. A small earthen causeway connected the man-made island with that of Fort Wool. The bridge-tunnel opened to traffic in 1957. The outmoded fort was finally abandoned by the military. After being decommissioned, it was given to the Commonwealth of Virginia in 1967 and in 1970, the City of Hampton developed it into a park. The Fort Wool passenger ferry, Miss Hampton II, allows tourists boarding in Hampton to visit the island during most of the year, but it can also be briefly glimpsed by passengers in westbound vehicles prior to entering the southern end of the tunnel portion of the Hampton Roads Bridge-Tunnel, which carries Interstate 64 across the mouth of the harbor. The island, now called Rip Raps, continues to settle in modern times, and occasionally the casemates of the original fortress are put off-limits for safety reasons. It remains a major draw for tourists, who usually include it in a visit to Fort Monroe. During the summer months, it is served by various harbor tour boats.