  Emergent magnetic fields exerted by topological spin textures of magnets lead
to an additional Hall response of itinerant carriers called the topological
Hall effect (THE). While THE as a bulk effect has been widely studied, THE
driven by magnetic domain boundaries (DBs) has been elusive. Here, we report
rich Hall responses characterized by multiple peak structures and a hysteresis
loop in films of EuCd$_2$, where Eu layers form a geometrically frustrated
lattice of Heisenberg spins. We uncover a THE component sharply enhanced at
magnetic transition fields, indicating a giant contribution from non-trivial
spin textures possibly formed at the DBs.
