Tidal inlets are among the most dynamic of landforms and leave a geological legacy within coastal barrier systems. Background document analysis of the historic Cranbury Inlet (also known as New or Cranbury Inlet, New Jersey, USA), suggests much debate surrounding the years of its opening and a relatively poorly constrained migration history. According to coastal charts and maps dating back to the early 1700s, there have been numerous inlets along the wave-dominated central New Jersey coast but due to the unstable location and the cross-sectional area, most of them had closed or migrated, leaving little surficial evidence of their existence. Cranbury Inlet was located south of Mantoloking Beach (a breach from the 2012 Superstorm Sandy), between Barnegat Inlet in the south and the historic Herring Inlet in the north. A large channel connected Barnegat Bay with the Atlantic Ocean and was a key artery for navigation and historic Revolutionary War battles. The timing of its opening has varied from 1740 to 1760. The channel location was unclear, and some sources described it to be several km north of the Toms River mouth, while others claim it was located at the current Ortley Beach. My historical document research helped to establish a more accurate timing of the Cranbury Inlet opening between 1738-1747. The migration path and the final location of the inlet were also confirmed using a first-ever set of geophysical surveys collected along this section of the coast. This study employed a 500 MHz ground-penetrating radar (GPR) to test whether a channel sequence can be identified below an intensely developed barrier segment and to help locate the closure site of the inlet channel. With more than 3 km of high-resolution GPR images, I was able to locate the northern margin of the historic inlet and its migration to the south, consistent with the longshore transport direction. My study confirms that Cranbury Inlet was at least 4-5 m deep and started filling up several years before closing in 1812, gradually shoaling more each year until it was finally closed. In the following century, there were several failed attempts to reopen the channel. My study also helped to reveal that in 1821, there was another inlet in a close proximity to Cranbury Inlet, which most likely was opened due to an intense storm and did not stay active for a long time. Geophysical imaging confirms the presence of Cranbury Inlet seaward of a lobate region, terminating in the north at West Point Island. The latter is likely a large flood-tidal delta complex with relict ebb-shield and ebb-spits, with several undeveloped marsh-covered islands to the south representing the path of a rapidly migrating inlet prior to its closure. The paleo-inlet complex remains as a site of inverted stratigraphy (fining-upward sequence), with implications for hydrologic structure (saltwater intrusion) and stability of the barrier. / Geology