This sick race has become well known after this video from the 2010 course went viral, click the link below to check it out:

VCA 2010 RACE RUN from changoman on Vimeo.

Other urban downhill races:

Lisboa Downtown
http://lisboadowntown.sapo.pt/

Cagliari King of the Castle
http://www.goodlooking.it/events.php?id_event=24

Townhill Bergamo
http://www.townhill.eu/

Itchimbía DH
http://afuera.com.ec/eventos/mas-fotos-del-itchimbia-dh/

Note: I couldn't figure out the exact location of the race, so the map below simply points to a random spot in Valparaiso.