We study the magnetic response of superconducting γ -Ga via low temperature scanning tunneling microscopy
and spectroscopy. The magnetic vortex cores rely substantially on the Ga geometry, and exhibit an unexpectedly
large axial elongation with aspect ratio up to 40 in rectangular Ga nanostrips (width l < 100 nm). This is in stark
contrast with the isotropic circular vortex core in a larger round-shaped Ga island. We suggest that the unusual
elongated vortices in Ga nanostrips originate from geometric confinement effect probably via the strong repulsive
interaction between the vortices and Meissner screening currents at the sample edge. Our finding provides novel
conceptual insights into the geometrical confinement effect on magnetic vortices and forms the basis for the
technological applications of superconductors.