Complex sentence: Cole Valley grew up around the streetcar stop at the entrance the Sunset Tunnel, at the intersection of Carl and Cole Streets; that intersection is still the center of the neighborhood's small business district, and the N Judah light rail line still stops there.
Split into simpler sentences: Cole Valley grew up around the streetcar stop at the entrance to the Sunset Tunnel at the intersection of Carl and Cole Streets. That intersection is still the center of the neighborhood's small business district, and the N Judah light rail line still stops there.