Here's a map of LA's original Chinatown, which was mostly located east of Alameda, where Union Station is now:
From lapl.org
And here's a map of El Pueblo de Los Angeles Historical Monument, which includes Olvera Street and the Plaza where LA began as a little pueblo. But see, so much was destroyed to build the freeway ramps, and create landscaping (and a surface parking lot). Los Angeles Street was rerouted at its northern end to curve east and intersect with Alameda in front of the main Union Station entrance. The sharp triangular block of buildings where Los Angeles Street originally intersected with Alameda is now a little plaza with a fountain. The map is turned so that the South/North orientation is going left/right:
From lacity.org