Complex sentence: Beneath the grill, in the traffic island in the middle of the road, can be seen the old road signs for the now-vanished Little Compton Street, which once joined Old Compton Street with New Compton Street.
Split into simpler sentences: Beneath the grille in the traffic island in the middle of the road, the old road signs for the now-vanished Little Compton Street can be seen. This road once joined Old Compton Street with New Compton Street.