Directions:

All sites pertaining to vanadium are in the Centro Histórico (historic center) of Mexico City.
Palacio de Minería, "Palace of Mineralogy,"5 Tacuba - N19 26.15 W99 8.38.
Real Seminaro de Minería (Royal School of Mineralogy), site of vanadium (erythronium) discovery, 90 Republica de Guatemala - N19 26.06 W99 07.70.
Humboldt's home during his visit to Mexico, 80 Rep de Uruguay - N19 25.82 W99 08.12.
Humboldt's statue, presented to Mexico from Germany, 90 Republica de Uruguay (SE corner of Republica de Uruguay and Isabela La Cátolica) - N19 25.83 W99 08.20.