  Topological concepts have been employed to understand the ground states of
many strongly correlated systems, but it is still quite unclear if and how
topology manifests itself in the relaxation dynamics. Here we uncover emergent
topological phenomena in the time evolution of far-from-equilibrium
one-dimensional interacting bosons. Beginning with simple product states, the
system evolves into long-time stationary states with high energy that are
nonthermal for a wide range of parameters, and they exhibit nonlocal string
correlation that is characteristic of the symmetry-protected topological ground
state of the Hamiltonian. In contrast, no topological feature is found in the
stationary state as long as the system thermalizes. This difference is further
corroborated by the distinct behaviour of quantum entanglement and edge states
of the system. Our theoretical prediction can be examined by current
experimental techniques and paves the way for a more comprehensive
understanding of topological phases in nonequilibrium settings.
