[ugvaecin] convenient volcanic land bridge

when has a volcano's lava flow into water conveniently built a bridge over a gap that humans wanted to bridge?

there must be evidence of regular human crossings (over water) before the eruption.  there must now be a road across the land bridge.

Sakurajima, Japan is one possible example.  but the road is there (in part) to visit the volcano famous for the 1914 eruption that created the land bridge.  is (was) there demand for travel to the peninsula (island) apart from that?