A tour through Los Angeles can be a bit like driving through one big, palm tree-lined cemetery. Lurking about the city’s grimy streets, manicured lawns and dusty canyons are homages to Hollywood’s dark past, from long-abandoned mansions to the iconic Hollywood sign itself where the aspiring starlet Peg Entwistle leapt to her death from the “H” in 1932, back when it still read Hollywoodland. (Her spirit is said to wander the nearby Griffith Park trails.) Perhaps because so many travel to Los Angeles with soaring expectations, the city — unwilling to embrace every fresh, new face — feels suffused with melancholy.

Ms. Entwistle’s short career as siren and her untimely death at the age of 24 are emblematic of the strange dichotomy of the city: sparkling, yet dark; seductive, yet scary. Just beneath a shiny surface lies a graveyard of secrets and dirt. All around the city, from Hollywood to Compton, the duality of glitter in the dark is on view; you just have to know where to look. Fortunately for the noir-curious, an entire branch of tourism trafficks in the city’s underbelly. Call it Morbid Los Angeles.

For the bookish fan of the macabre, there’s Esotouric (esotouric.com), a company run by Kim Cooper and Richard Schave, local social historians and true-crime enthusiasts. Their crime scene bus tours, which began in 2005, grew out of a mutual love of Raymond Chandler and forgotten scandals.