  The physical mechanism of gamma-ray bursts (GRBs) remains elusive. One of the
difficulties in nailing down their physical mechanism comes from the fact that
there has been no clear observational evidence on how far from the central
engine the prompt gamma-rays of GRBs are emitted while the competing physical
mechanisms predict different characteristic distances. Here we present a simple
study addressing this question by making use of the "high-latitude emission"
(HLE). We show that our detailed numerical modeling exhibits a clear signature
of HLE in the decaying phase of "broad pulses" of GRBs. We show that the HLE
can emerge as a prominent spectral break in $F_{\nu}$ spectra and dominate the
peak of $\nu F_{\nu}$ spectra even while the "line-of-sight emission" (LoSE) is
still ongoing, hence providing a new view of HLE emergence. We remark that this
"HLE break" could be hidden in some broad pulses, depending on the proximity
between the peak energies of the LoSE and the HLE. Also, we present three
examples of Fermi-GBM GRBs with broad pulses that exhibit the HLE signature. We
show that their gamma-ray emitting region should be located at $\sim 10^{16}$
cm from the central engine, which disfavors the photosphere models and
small-radii internal shock models but favors magnetic dissipation models with a
large emission radius.
